mkstub is the tool used to stub the google_apis maps.jar.
Since we're integrating it in the build, we want to control its verbosity.
Change-Id: I93d7dc6a63426affac008f8ef367a0d79277b59a
This also reorganizes some source so it's 90% refactoring.
There will be more filtering to do in another CL.
Original author: raphael
Merged from: //branches/cupcake/...
Original author: android-build
Automated import of CL 146829