This should still be consistent with the previous behavior, down to
the output aar paths and support for Maven. Some highlights:
- Some Gradle files move to the top level of the repository so IDEs
can pick them up when opening the repo root.
- javadoc is now handled through Gradle (though build-javadoc still
exists as a thin wrapper).
- The "dependencies" we were pulling down weren't really needed at
all.
