As announced: https://groups.google.com/forum/#!topic/protobuf/VX5qEmTW3y0

The ObjC side of https://github.com/google/protobuf/issues/272

Fixes https://github.com/google/protobuf/issues/3164.

Adds serial and parallel parsing tests to check if parallel parsing is faster than serial parsing, which it should

- Fix up -copyWithZone: to not leave the two registries sharing
  some of the storage by using -addExtensions:.
- Improve -addExtensions: to clone the sub dict when there is
  nothing to merge into.
- A ExtensionRegistry unittests.
- Update project schemes to not have extra things in perf scheme.

GPBMessageDropUnknownFieldsRecursively() is a new helper to drop the
unknownFields from a message and all sub messages (in fields or extensions).

- The Timestamp proto does not allow for negative nanos fields, so the seconds
  must be shifted and a positive nanos then applied.
- Tweak the helpers on Duration to make it clear there is no "base" time
  involved.
- Update the unittests for duration and timestamp to cover positive and
  negative NSTimeIntervals and what their impact is on the protos.

The Timestamp proto does not allow for negative nanos fields, so the seconds must be shifted and
a positive nanos then applied.

- If setting/clearing a repeated field/map that was objects, check the class
  before checking the autocreator.
- Just to be paranoid, don’t mutate within copy/mutableCopy for the autocreated
  classes to ensure there is less chance of issues if someone does something
  really crazy threading wise.
- Some more tests for the internal AutocreatedArray/AutocreatedDictionary
  classes to ensure things are working as expected.
- Add Xcode 8.2 to the full_mac_build.sh supported list.

- Check the parent file options for deprecation when deciding to tag Messages
  and Enums as deprecated.
- Within the generated source push/pop the warning for implementing deprecated
  things around a deprecated class implementation.
- Annotate the methods generated for extension fields as deprecated.
- Add a testing .proto file that covers deprecated fields, messages, enums,
  enum values and compile it into the unittests to confirm things compile
  cleanly.
- Add a testing .proto file that uses the file level option to make everything
  deprecated and compile it into the unittests to confirm things compile
  cleanly.

- Let Xcode 8 update settings on the projects/schemes.
- Migrate Swift tests to Swift 3 syntax.
- Update the build/test script:
  - Require Xcode 8 (because of the Swift 3 requirement for tests)
  - Update the devices to what Xcode 8 has (8.x simulator seem to fail even
    though they can be downloaded in Xcode 8)
- Update the travis images to ones with Xcode 8.

- Capture the ObjC prefix used when generating the the file.
- Track the containing type on descriptors.
- Mark descriptors where the message class name got a suffix added to it.
- Expose a fullName property on Descriptors.
- Add helpers for packing/unpacking Any messages.
- Bump the ObjC runtime version number. Since we added methods and invoke them
  in the generated code, ensure the code is running against a matching version.
  Otherwise, someone could compile against headers, but run with a framework
  that is older and get unknown selector failures.  This should trip clearer
  messaging.

Fixes https://github.com/google/protobuf/issues/1674

At generation time, walk the file's dependencies to see what really contains
extensions so we can generate more minimal code that only links together the
roots that provided extensions. Gets a bunch of otherwise noop code out of
the call flow when the roots are +initialized.

If a message is proto3, then the zero values still count as being set one the
field is in a oneof.

Add tests to confirm oneofs work as expected in both syntaxes.

Fixes https://github.com/google/protobuf/issues/1933

Add a new test that forces strings into two different implementations from the
NSString class cluster to help confirm we're exercising both paths by which
CodedOutputStream will extract data from an NSString.

Move the old +load test (that was flawed because the behavior really depends on
the type of string from the NSString class cluster); into a unittest that
targets the specific case we're adding a behavior confirmation on.

As a bonus, improve the TextFormat generation of string characters < 0x20.

Convert mapping of proto comments to appledoc format so they show up in Xcode and cocoadocs.

Fixes https://github.com/google/protobuf/issues/1866

Code already works, but make a bank of tests that call it out so things are
very clean in the future just to be safe.

If a message is proto3, then the zero values still count as being set one the
field is in a oneof.

Add tests to confirm oneofs work as expected in both syntaxes.

Fixes https://github.com/google/protobuf/issues/1933

Add a new test that forces strings into two different implementations from the
NSString class cluster to help confirm we're exercising both paths by which
CodedOutputStream will extract data from an NSString.

Move the old +load test (that was flawed because the behavior really depends on
the type of string from the NSString class cluster); into a unittest that
targets the specific case we're adding a behavior confirmation on.

As a bonus, improve the TextFormat generation of string characters < 0x20.

Convert mapping of proto comments to appledoc format so they show up in Xcode and cocoadocs.

Fixes https://github.com/google/protobuf/issues/1866

Add the `nullable` qualifier to return types of Objective-C methods that
can return a nil due to errors. This change makes these methods
compatible with the Swift 2 try-catch syntax.

- Correct some cases sources were compiled into the static lib and the tests.
- Enable Xcodes code coverage support on the unittests.  We aren't complete on
  coverage, but having the data always there should make it easier to chip away
  at this going forward.
- Drop method in tests that isn't used, wire up a validator in another test.

- Correct impl by using helpers the message wiring does.
- Add unittests.

Fixes https://github.com/google/protobuf/issues/1716

Note: Breaking API change on the Dictionary classes.

The numeric value classes were using "Value" in the naming, but this silently
collided with the KVC category on NSObject; meaning KVC code could break up a
keypath and call these selectors with the wrong types leading to crashes (even
though the code all would compile cleanly).

- Rename the methods to use the "type" instead of literal "Value".
- Update all the impls and tests.
- Enable the warning that will catch issues like this in the future.

Fixes https://github.com/google/protobuf/issues/1616

Adds destination flag to xcodebuild to avoid possible flake errors

Also hotwires updating ruby as CocoaPods was crashing within a support library.

Fixes #1619 

Add more context to GPBCodedInputStream failures.
Have GPBMessage parsing apis extract out the GPBCodedInputStream information and expose it.
Update HeaderDocs with pointers to all error domains/codes.
Expand the unittests to cover the full set of errors reported.

Fixes https://github.com/google/protobuf/issues/1618

This is currently checking for the wrong class for enums
and NSMutableArray fields.

- Add generator constant for the default framework name.
- Add generator api for making the CPP symbol from the name.
- Add generator api to see if it is a bundled proto file.
- Output a CPP conditional and two imports for the core library headers.
- Add helper for generating the #import for file headers to deal with the
  framework imports.
- Add a reference from the unittests to a WKT to use that to inspect how
  imports generate.
- Update the podspec to define the CPP symbol and require pods 1.0 (or later).

Fixes https://github.com/google/protobuf/issues/1457

- Env solution doesn't seem to always work, use template pod files and copy
  them in place instead.
- Flush the pods cache before and after runs.
- Make pod install verbose to have the info incase something goes wrong.

Otherwise the projects have to be opened once to create user schemes for the
command line builds to work.

- Add an Xcode 6.3 created default iOS Project.
- Add an Xcode 6.3 created default OS X Project.
- Add Podfiles to for both that use Protobufs from within the tree.
- Add a script to run the tests (and cleanup) to help confirm the state of the
  Protobuf.podspec and sources.

Both methods weren't checking the has_bits (where the bools are stored), so
it resulted in invalid results.

Add a test that should shake out something like this in the future also.