Add a stub torquebox-scheduling gem, cleanup the Rakefile

The Rakefile was modified to support the idea of multiple gems inside
one source tree, with a way to build/clean/release all from the top
level. The compiling options were also made a bit more generic so the
other TorqueBox gems can reuse the same maven resolution compilation logic.

This also prompted me to take time to remove 'jbundle install' as a
requirement and instead call jbundler during our rake tasks, resolving
dependencies as needed.