CAY-1883 - Clean up Cayenne maven structure - get rid of aggregate modules

* no more direct dependencies on hsqldb (only included in the test profile)
* aligning derby dep versions

git-svn-id: https://svn.apache.org/repos/asf/cayenne/main/trunk@1542589 13f79535-47bb-0310-9956-ffa450edef68
CAY-1883 - Clean up Cayenne maven structure - get rid of aggregate modules

* cleanup, being explicit about the scope of
  various dependencies

git-svn-id: https://svn.apache.org/repos/asf/cayenne/main/trunk@1542590 13f79535-47bb-0310-9956-ffa450edef68