Merge github.com:grpc/grpc into so-freaking-sick-of-irrelevant-merge-conflicts

BUILD

gRPC.podspec

src/compiler/objective_c_plugin.cc

src/objective-c/GRPCClient/GRPCCall.h

src/objective-c/GRPCClient/GRPCCall.m

src/objective-c/GRPCClient/private/GRPCDelegateWrapper.m

...ctive-c/GRPCClient/private/GRPCMethodName+HTTP2Encoding.h

src/objective-c/GRPCClient/private/NSError+GRPC.m

src/objective-c/ProtoRPC/ProtoRPC.h

src/objective-c/ProtoRPC/ProtoRPC.m

src/objective-c/ProtoRPC/ProtoService.m

src/objective-c/RxLibrary/transformations/GRXMappingWriter.h

src/objective-c/examples/Sample/Sample/ViewController.m

src/objective-c/tests/GRPCClientTests.m

src/objective-c/tests/InteropTests.m

src/objective-c/tests/LocalClearTextTests.m

src/objective-c/tests/RxLibraryUnitTests.m

templates/BUILD.template

templates/gRPC.podspec.template