Allow grpc_init to be called multiple times

Python interop server.

Temporarily pauses some tests

Fix fling test leaks

Fix aliasing

Unix domain socket support

Conflicts:
	Makefile

Add support for out of tree builds

Adding an NMake makefile for Windows

Avoid four allocations per stream

Conflicts:
	Makefile
	templates/Makefile.template

Documentation tweaks in grpc.h.

Auto-dependency building doesn't do this (yet)

Properly msan-instrumenting protobuf and our C++ tests

Cleaning up our posix definition / usage.

Fix time header file for Mac

Renaming the docker image to grpc_clang, and optimizing the build a bit.

-) Let's not use _POSIX_SOURCE. It usually implies too much C99. _BSD_SOURCE would be the right thing to do here.
-) _BSD_SOURCE is getting deprecated by glibc, so we also have to define _DEFAULT_SOURCE under Linux.
-) accept4 and eventfd arn't as old as we may think; let's detect for it.
-) stdint.h interferes with all these definitions if included too early; let's move it down.