Introducing buck for building java code. This does not build everything.
It doesn't really build that much at all, but you can see it in action by
installing buck and running:

  buck build //java/client/src/org/openqa/selenium/lift:lift \
             //java/client/src/org/openqa/selenium/support:page-factory \
             //java/client/src/org/openqa/selenium/support:support
             chrome htmlunit

This appears to compile everything about three times faster than the same
crazy-fun incantation.