Add stub/unstub libraries as submodules.
Configure GitHub-hosted Maven repository in `mvn-repo` branch of `mozilla-services/android-sync`.
Use latest Android platform (version 17).
Update Vagrant and Puppet virtual machine provisioning.
Update documentation.
GitHub does not implement ReST's include directive, so preprocess README.rst from README.rst.in.
Configure GitHub-hosted Maven repository in `mvn-repo` branch of `mozilla-services/android-sync`. r=rnewman