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.

update the OSGi metadata for the javanano package

Speed up ObjC Generation with large dependency trees

Don't create FileGenerators for each dep. FileGenerators will deeply create all
the message, enum, and field generators; but those aren't needed when doing
the imports for dependencies. Instead directly generate the imports off the
FileDescriptors so no extra objects are created. The only other use was when
chaining together the *Roots for the file extension registry, but that also
can be generate off the name of the FileDescriptor directly.

Ruby: make sure map parsing frames are GC-rooted.

Fix missing import of jspb.Map (#1885)

ObjC support for GenerateAll().

- Expect calls on GenerateAll() and not Generate().
- Parse the prefix validation file once, and then check all the files.

Update gmock links.

Change-Id: I3d44e3c6877e00cfea5a903568fde1e6f597aac1

The original link is no longer available.

Change-Id: I2976d3f19c8e818689549fb31ff20af8eae92a07

Add an Erlang project, gpb, to third_party.md

Fixing regular expression...

This will allow loading the extension for Ruby 2.1.10...

Move ImportWriter into helpers for sharing

Breaks the tie of the ImportWriter to the ObjC generation, allow grpc to use
a different extension and to relay the values they need for these.

- Pass in the two framework options to the ctor.
- Pass in the header extension to AddFile.

grpc likely needs to provide the same sorta handling, so expose the class so
the logic can be reused.

Add note about JSON tests maybe being wrong.

- Add note about the JSON test maybe not being correct yet.
- Add test to checks the generated names for double underscores to be sure they
  are what is expected.

More tests to shake out some cases in the json parsing

- String behaviors
- Testing only valid JSON is allowed

Adds better support for protos without packages and more warnings on possible improvements

Fixes #1844 

Add more JSON tests around underscores

Add a jenkins test status badge.

Fix up ignores and conformance generation

- Update ruby conformance generation for rename of generated files that seems
  to have happened.
- Update gitignores for the above and for the no-warnings-test.

Regenerate conformance files to include extra oneof fields.

This should fix the failures in the conformance tests - although
it highlights the problem that we need to do this when changing
the conformance.proto file...

[ci skip]

Change-Id: I5bf4f204e7ef0144d8fc984a985d502f92ce95ce

Fixes extra whitespace on generated comments.

Objc more reset tests

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.

Objc fix oneof zeros and more oneof zero conformance tests