Merge branch 'master' into wheezy

examples/python/route_guide/route_guide_server.py

src/core/ext/client_config/lb_policy.c

src/cpp/server/server_posix.cc

src/objective-c/GRPCClient/GRPCCall.m

src/php/bin/stress_client.sh

src/php/tests/interop/stress_client.php

src/python/grpcio/grpc/__init__.py

src/python/grpcio/grpc/_adapter/_types.py

src/python/grpcio/grpc/_common.py

src/python/grpcio/grpc/_cython/_cygrpc/records.pyx.pxi

src/python/grpcio/grpc/beta/interfaces.py

src/python/grpcio/tests/qps/benchmark_client.py

src/python/grpcio/tests/tests.json

src/python/grpcio/tests/unit/_api_test.py

src/python/grpcio/tests/unit/_from_grpc_import_star.py

src/python/grpcio/tests/unit/_metadata_test.py

...thon/grpcio/tests/unit/beta/_connectivity_channel_test.py

templates/tools/dockerfile/run_tests_addons.include

templates/tools/dockerfile/run_tests_addons_nocache.include

...e/stress_test/grpc_interop_stress_php/Dockerfile.template