Include well-known types in Java runtime.

Change-Id: I816fe2fac7fccbcd96dd8510c7c9b5e7996aeadc

Adds a podspec for the proto3 Objective-C runtime.

Getting the ObjC generator building on Windows.

Solves AOT compilation issue for Unity - iOS

added concrete IEqualityComparer<ExtensionIntPair> implementation in ExtensionRegistryLite.cs to prevent AOT compilation issue with unity in iOS

Marked compiler literal unsigned.

C# travis integration

When compiling a protobuf with gcc 3.3.2 for powerpc, I ran into the
following warning message:

INFO: From Compiling my_proto.pb.cc powerpc-603e-linux-gcc:
bazel-out/local_linux-dbg/genfiles/my_proto.pb.cc: In member
   function `virtual void MyProto::Clear()':
   bazel-out/local_linux-dbg/genfiles/my_proto.pb.cc:223: warning: this
      decimal constant is unsigned only in ISO C90

The line in the proto file that was triggering it was:

  if (_has_bits_[24 / 32] & 4278190080) {
    ZR_(field1_, field2_);
  }

_has_bits_ is a uint32.  The constant mask should therefore be
unsigned.  This change updates the constant to be generated as
unsigned.

Remove the ClassList support (maybe bring it back in the future).
Trim the includes to hopefully get a working Window build.
Add some more returns after switches for compilers that warn even when all values of the enum are handled.
Use ghtonl instead of htonl.
Change the use of [u]int(8,32)_t within the ObjC generator code to [u]int(8,32) to match the rest of the compiler.
Add objective-c generator files to Visual Studio project.

Ruby C extension speedup: don't re-intern constant string needlessly.

Also fixed lines with > 80 char length.

Generate *all* protos in the script, applying fixups.

Update MRI C Ruby extension to use new version of upb (with upb_env).

Post csharp landing fixup.

Re-add the objc prefix that got removed by accident.
Regenerate the generated descriptors (C++ and ObjC).

We still have some protos which aren't generated how we want them to be:

- Until we have an option to specify the "umbrella" class, DescriptorProtoFile
  will be broken. (The change of name here affects the reflection descriptor,
  which accounts for most of the change. That's easier than trying to work out
  exactly which occurrences of Descriptor need changing though.)
- That change affects UnittestCustomOptions
- Issue #307 breaks Unittest.cs

After this commit, we don't have the record of the fixups in the files themselves
any more, but one centralized record in the shell script.

[PYTHON] Only generate protos in development

Fixes #333.

- Alter encode/decode paths to use the `upb_env` (environment)
  abstraction.
- Update upb amalgamation to upstream `93791bfe`.
- Fix a compilation warning (void*->char* cast).
- Modify build flags so that upb doesn't produce warnings -- the Travis
  build logs were pretty cluttered previously.

ruby: Encode decode cleanup and behavior normalization

Make generate_protos.sh Windows-friendly.

Apparently, in Cocoapods, all recursive #imports of public headers need
to be public.

Refactor Travis tests: split configs and run in parallel.

Merge protobuf C# into master (only C# proto2 is supported)

ruby: make repeated_field quack like an array

To my surprise, executing generate_protos.sh used the version of Bash installed with Git for Windows by default.
After a few modifications to detect the most appropriate protoc to use, this worked pretty simply.
This change also:
- adds generation of the address book tutorial proto,
- fixes the addressbook.proto to specify proto2 explicitly (to avoid a warning from protoc; I don't think we want warnings...)
- fixes the addressbook.proto C# namespace (which I thought I'd done before, but apparently hadn't)
- includes the regenerated UnittestCustomOptions.cs apart from the DescriptorProtoFIle => Descriptor change

Add Ruby to Travis testing

Integrate changes from latest master branch into csharp branch.