* Rewrite lint.sh as check_lint.py
This makes several beneficial changes:
* Runs in parallel: lint all now takes 5.5 seconds, down from 25.
* Supports linting specific files, passed on the command-line.
* Defaults to linting files changed since master, pass --all to lint
everything.
* Infers header language based on related files.
* Lays the groundwork for linting more than just C++.
* Adds support for linting python.
* Fix lint errors
* Use check_lint.py in check.sh
* Remove lint.sh
* Python lint configuration
* Enable python linting in travis
* Add classes in testutil and util to the project
* Exclude util/iterator_adaptors_test which requires gmock
* Exclude remote/serializer_test which is missing some paths
* Add iterator_adaptors_test and add gmock support
* Add gmock support to the GoogleTest podspec we vendor
* Add iterator_adaptors_test.cc to the Xcode project
* Add a script that verifies all tests are referenced in the project
* Add a travis check that all tests are referenced in the project
* Review feedback
* Moar feedback
Gil