OSGi support

The OSGi tests still log too much when they fail (otherwise the log output is suppressed by junit-interface). Apart from that it looks good. I think we should merge this now and get 2.11-M1 with OSGi support out so that we can do the same for slick-extensions (which requires a published Slick JAR with OSGi). I changed the database test from lifted embedding to plain SQL to cut down the logs. Even for a failed test it's only about one page now. Review by @cvogt, cc @jsuereth