[FELIX-4370] Additional work to support the OSGi Repository Service.

Added better support for directives.
This also fixes an OSGi Repository CT failure:
  RepositoryTest.testRepositoryContent2()
Also added a bunch of unit tests for areas not completely covered by the CT.



git-svn-id: https://svn.apache.org/repos/asf/felix/trunk@1591870 13f79535-47bb-0310-9956-ffa450edef68