Beta quality drop of Objective C Support.

Refactored the threadlocal logic for Android and IOS into logic in
platform_macro.h which computes a GOOGLE_PROTOBUF_NO_THREADLOCAL
define which is then used elsewhere.  This allows new platforms
without THREADLOCAL to be easily defined.

- Add more to the ObjC dir readme.
- Merge the ExtensionField and ExtensionDescriptor to reduce overhead.
- Fix an initialization race.
- Clean up the Xcode schemes.
- Remove the class/enum filter.
- Remove some forced inline that were bloating things without proof of performance wins.
- Rename some internal types to avoid conflicts with the well know types protos.
- Drop the use of ApplyFunctions to the compiler/optimizer can do what it wants.
- Better document some possible future improvements.
- Add missing support for parsing repeated primitive fields in packed or unpacked forms.
- Improve -hash.
- Add *Count for repeated and map<> fields to avoid auto create when checking for them being set.

Remove vsprojects.

Speed up little endian int/long writes.

Marked another compiler literal unsigned.

Fixed bug in GOOGLE_PREDICT_FALSE.

Make it executable and generate extract_includes.bat in the same directory.

When compiling a protobuf with gcc 4.1.2 for powerpc, I ran into
another of 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.

The GOOGLE_PREDICT_FALSE macro is both incorrect, and doesn't match
the macro definition in glog, which causes conflicts when including
both libraries.  This commit fixes that by making it identical to
what is in glog.

Conformance tests can now be excluded based on their names.

Migrate writer to printer for C#

Change-Id: I382dcda97fa123a6da4ff5faad5d7ece95853f33

Add cmake support.

Change-Id: I121cb70bfdc4894c297ab1a36f1db47736c0652b

Remove Android.mk

This allows us to enable conformance tests even when we know
that some tests are failing and need to be fixed.

Change-Id: I372f43663008747db6f2b2cf06e6ffa4c6d85b2d

Add protoc path detection for Mac OS

This file bares a different copyright license and also doesn't actually
work (out-dated file lists, no config.h/pbconfig.h, refers to inexist
AOSP paths).

Fix two issues on vs2010.

Add remaining not-already-imported well known types files to podspec

Fix unittest in i386

Document why the podspec is on the root of the repo

A few corrections to the proposed podspec

Change the C# enum generator inherit from primitive generator