Add sqlite dependency, cleanup omnibus.rb

This adds a dependency on sqlite (so that gwm can use sqlite as a db). Unfortunately, it is also good to compile python after sqlite, so I pulled in the python config and added the sqlite dependency there as well.

I also cleaned up omnibus.rb so that you can build in a different dir by just setting <code>export GWM_PREFIX=./local/omnibus</code> or wherever you like. No need to change the files/reset them before pushing.