Improvements to lb_policies_test's rebirth testcase.

Release 0.11 to master upmerge.

Drop issue 527 TODOs for UnaryCall interop test specification

PHP: fix watchConnectivityState unit test

Fixes broken build due to misplaced import

Use only "#!/usr/bin/env python2.7" Python shebang in utilities

Add gyp file for compiling C core

The GRPCCall import must be in the header because it defines a protocol
that GRPCRequestHeaders uses.

Changed GRPCCall import to class forward declaration

The GRPCCall.h file is already correctly imported in the
GRPCRequestHeaders.m implementation file. This header shouldn’t need to
import GRPCCall and should specify a class forward declaration for
reference.

Fixing Makefile issue which would re-evaluate the base path for included dependency files.

Prevent failed docker builds from accumulating

The UnaryCall interop test is now adequately specified in
doc/interop-test-descriptions.md.

PHP: jenkins flakes

By default docker does not clean up temporary images when the build
fails to allow the user to inspect the state of the container to
determine what went wrong. Those images don't help us at all and just
accumulate until disk usage is 100%.

Fixing usage of the BUILDDIR variable.

Move content-type handling code across to 0.11

Update protobuf submodule to fix Objective-C

bump version of C# to 0.7.1

Fixing sanity.

Fix mutex bug

Update to nan 2.0

It is a bad idea to have a map with string_refs as output params.

Do not use string_ref for output params.

Fix Python dockerfile.

Update Python release number to 0.11.0b1.

Now both using absolute and relative directory for that variable should work.

  BUILDDIR=/tmp/build-grpc make
  BUILDDIR=../build-grpc make