First cut at OSGi-fun for slick.

* Add sbt-osgi plugin
* Create really really stupid defaults for slick OSGi bundle
* Create new project to run slick OSGi tests
  - We have to fork for who knows why
  - We pass bundles to load via a system property (may be windows unfriendly)
* Create the most basic of basic tests, just to ensure we load/link things in the OSGi world.
Improve OSGi integration:

- Turn down logging for the container and the service log. The actual
  test logs are unaffected.

- Remove osgiTest project from root aggregation. It is not published
  and tests are not run by default. They are still run as part of
  testAll.

- Add H2 driver to OSGi test and run an actual database test.

- Rearrange package structure.
Clean up dependencies
Merge pull request #752 from slick/tmp/osgi

OSGi support