This does not affect the generated code.
If we decide we want to apply attributes to generated types, we should start by
just reverting this change.

I think this has caught everything.
I've left a stub for attributes to be applied to the types themselves, but we don't currently need anything.

Follow-up commit will include the changes to generated code itself.

Fixes #1671.

Change-Id: Ibf7d1df850f4b497303f9f617751be98327898ef

This includes all internal changes from around May 20 to now.

- add JsonParseOptions for JsonToBinaryString allow unknown fields
- rename current JsonOptions to JsonPrintOptions

- Better docs in the generator for the different options that can be passed
  during an invoke of protoc.
- Add named_framework_to_proto_path_mappings_path to pass the path to a file
  containing mappings of frameworks for different proto files.
- Update the generation to use the mapping to change the #import directives
  it creates.

Note: the changes in helpers is mostly moving code within the fine, and then
a small change to expose the parsing so a passed on class can consume the line.

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

constructor, and instead create an _internal_only getter
that gets the needed information. This is a workaround for
a deficiency in gcc-4.4 that does not properly support
templated friend classes.

- Add a protoc objc option (generate_for_named_framework) to set the name of
  the framework all generated sources will be in.
- Tweak some comments/naming to make it clear what is the Protobuf framework
  vs. the framework for generated code.
- Update the objc README to document the new generation option to protoc.

This is working towards https://github.com/google/protobuf/issues/1457.

Working on https://github.com/google/protobuf/issues/1599, specifically:
- Turn on more warnings that the Xcode UI calls out with individual controls.
- Manually add:
  -Wundef
  -Wswitch-enum
- Manually add and then diable in the unittests because of XCTest's headers:
  -Wreserved-id-macro
  -Wdocumentation-unknown-command
- Manually add -Wdirect-ivar-access, but disable it for the unittests and in
  the library code (via #pragmas to suppress it). This is done so proto users
  can enable the warning.

- 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

This got broken in commit 6ef984af
which integrated changes from internal branch.

The commit 3b3c8abb has replaced the <>
with "" in #include statement in js_generator.cc

As it may be implementation dependent.

This time move the macro inside namespaces; hopefully will work with the
integration script.

proto2 syntax allows the first enum to have a non zero value. This means any
field using that default has a non zero default without having an explicit
default being set. So when deciding what runtime info is needed, don't rely
on an explicit default, always check that the values aren't zero.

Fixes https://github.com/google/protobuf/issues/1453

A protobuf message will be corrupted in the following scenario:
  1. Use LITE_RUNTIME.
  2. Have an optional enum field following some other field.
  3. Update protocol by adding new values to the enum.
  4. Have an old client parse and serialize a message having enum field
      set to a value the client does not understand.
  5. Field preceeding the enum is now corrupted.

The bug is due to the fact that optimized fallthrough in parser code
does not update variablle 'tag' when jumping to the parser code for the
next field.

Overview of changes:
- A new C#-specific command-line option, legacy_enum_values to revert to the old behavior
- When legacy_enum_values isn't specified, we strip the enum name as a prefix, and PascalCase the value name
- A new attribute within the C# code so that we can always tell the original in-proto name

Regenerating the C# code with legacy_enum_values leads to code which still compiles and works - but
there's more still to do.

proto3.

Added a couple unit test proto3 files, for arena_lite and lite. Cloned
the proto3_arena_unittest to test some of the basics of generated code
(and to ensure that the generated proto3 test files are used by some
test).

It doesn't seem to be necessary here, and it pulls other testing headers
during compilation of release protobuf.

This will make it easier to change the enum value names, as it reduces the number of places they're used.