Added framework for generating/consuming benchmarking data sets.

Few tweaks to the rakefile to permit native gems compilation with the proto files generation.

Merge Google internal changes

Fix cp -r usage to be portable.

cp -r foo/ bar/ in linux will create a bar/foo directoy. In the
objectivec generate descritpor case, well known types will be created in
objectivec/google/google/protobuf/.. if the command is run under linux.

Adding the trailing period fixes the behavior inconsistency.

Added dig and bsearch_index to RepeatedField methods forwarded to array

This takes the code that was sitting in benchmarks/
already and makes it easier for language-specific
benchmarks to consume.  Future PRs will enhance this
so that the language-specific benchmarks can report
metrics back that will be tracked over time in PerfKit.

Fix up -hash/-isEqual: for bool storage.

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.

This fixes the test_acts_likes_an_array test in RepeatedFieldTest, which
checks that repeated fields respond to the same methods as regular Ruby
arrays. The bsearch_index and dig array methods seem to be new in Ruby
2.3 and so we should support those.

Updated upb and simplified ruby code a bit with new upb method.

Proper checking of enum with non zero default

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

Added serialVersionUID to ExtendableMessage.

* Add initial design doc for Swift protocol buffers.

Add a docs directory and move the third-party add-ons page here.

Change protobuf CPP proto generator to support the 'lite' option in

Remove googletest.h header from stringprintf.cc

Regenerate descriptor/well-known types for C#

(There are documentation changes and new fields in descriptor.proto that have resulted
in changes to the serialized descriptor, but no breaking changes for C#.)

ObjC support for failing the build in the generated WKTs are out of date

- Always generated into a temp directory so we can see if things changed.
- Add a flag to control exiting with error when stale vs updating.

This should let the continuous builds error out when ObjC needs to have the
checked in sources updated.

Enum casing in C#

Support Windows in gulpfile.js