Fixed grpc C++ plugin support.

grpc C++ plugin generates additional files, namely .grpc.pb.cc and
.grpc.pb.h. Adding these files to the outs of the _proto_gen rule, so
dependents don't complain about undeclared inclusions. Also, compiling
the .grpc.pb.cc requires additional header files from the grpc library,
so added //external:grpc_lib to the deps of the
cc_library. Clients are expected to declare that in their bazel
WORKSPACE, pointing it to @grpc//:grpc++{_unsecure}.

Add a modified patch from craigcitro@ to handle namespace sharing.

Added grpc plugin support to cc_proto_library.

cc_proto_library now supports use_grpc_plugin flag that passes
--plugin=protoc-gen-grpc=grpc_cpp_plugin to protoc compiler
invocation. grpc_cpp_plugin is assumed to be present as
//external:grpc_cpp_plugin, so clients can setup their WORKSPACE files
appropriately to point to grpc location using bind.

Require VS2015 in the solution file

Add atomics support for 32-bit PPC.

Added support for CommonJS require()

Support ObjC Generic Collections

Validate that end-group tags match their corresponding start-group tags

Some fixes for the most recent release notes.

- Extend GPB*ObjectDictionary to support generic syntax.
- Update the generator to output generics so the enclosed type is exposed for compiler checks.
- Use generics in a the public interfaces.
- Update the generated sources that are checked in.

"nodejs" does not exist on Travis, it appears.

List python_cpp as failing on OS X

Disable the xctool updates

In light of https://github.com/google/protobuf/issues/1232, disable the xctool
update so we stay on 0.2.7 which seems to work better.

Remove the passing of -newSimulatorInstance since the older xctool doesn't
support it.

Generate C# code whenever descriptor.proto changes

Added ALLOW_UNLIMITED_BINARY_PROTO macro and setting it when

Add more tests around merging wrappers

Removes redundant null pointer checks checks

Removed 'optional' from proto3 syntax file.

--allow_oversize_protos=true is passed to bazel build.
When this macro is set, SetTotalBytesLimit is called to remove
the 64MB limit on binary protos when during ParseFromString.

Move the xctool use of -reporter into a common spot and always use "plain" to get more readable logs on travis.

Move the xctool use of -reporter into a common spot and always use "plain" to get more readable logs on travis.