Fixing Windows's missing pollset_set.

Enrich census initialization and feature code

Supporting FreeBSD for Jenkins.

Add Node documentation generation

changes to allow VS solution/project generation and grpc.mak generation for c++ tests

Client connectivity API

Debugging support for lock-free stack to check for double-push and valid pop

 Adding option to force client auth on the server SSL creds.

Generated signed assemblies for C#

only use lowercase metadata keys in headers

Add STREAM_LENGTH and POOL_SIZE to test_constants

Remove explicit reference to nullptr

grpc namespace and not supported by older compilers. Not sure
why I didn't catch this earlier.

Rename grpc_channel_create to grpc_insecure_channel_create

Only one of these is used, and in only one place, as of this commit,
but they will be used widely after further development.

Exposed channel target and call peer in PHP

Canonicalize metadata keys in core

Make work with out-of-band oauth2 token more pleasant

Avoid implicit conversions in Ruby extension code

Conflicts:
	src/csharp/ext/grpc_csharp_ext.c

Conflicts:
	src/core/iomgr/tcp_server_windows.c

Cleanup in C# tests