Merge remote-tracking branch 'upstream/master' into sequential_con

.gitmodules

.travis.yml

BUILD

CMakeLists.txt

Makefile

PYTHON-MANIFEST.in

build.yaml

composer.json

doc/compression_cookbook.md

doc/images/compression_cookbook_incoming.png

doc/images/compression_cookbook_outgoing.png

examples/cpp/helloworld/Makefile

examples/cpp/route_guide/Makefile

examples/csharp/helloworld/README.md

examples/objective-c/auth_sample/Podfile

examples/objective-c/helloworld/Podfile

examples/objective-c/route_guide/Podfile

examples/php/README.md

examples/php/composer.json

examples/python/helloworld/run_codegen.sh