Cleaning up ruby extension code a bit.

Cleaning up our Makefile.

Add ability to create and handle precompiled binaries in Node library

Use wildcard address by default in QPS driver

Make Node library depend on BoringSSL and zlib, and only build them under Windows

Alternative ownership for global callbacks

Ensure sanity generate projects doesnt eat all available cpu

Add a virtual destructor for the ClientContext::GlobalCallbacks.

 -) Adding question marks to important tools so they can be overriden from environment variables.
 -) Removing all traces of -ldl since BoringSSL doesn't implement OpenSSL's DSO and doesn't require it.

Initialize census if not initialized yet and some features are available

Fix sanity

Add missing "support" import.

I have no idea how this mistake got through.

Bump gRPC version to 0.13 and get C# version autogenerated

Update C# dependencies

Fix copyright

Add compiler error diagnostics to Python setup

Make sure we embed openssl and zlib in C# artifacts

Make grpc_tcp_listener private.

Fix path where we check for ruby coverage report