bump versions to 4.0.0-SNAPSHOT
[PAXEXAM-620] prune some modules and compile under JDK 8
[PAXEXAM-620] compile with 1.7 source and target level
[PAXEXAM-520] Upgrade to OSGi 4.3.1
[PAXEXAM-621] Upgrade to Knopflerfish 6.0.4
[PAXEXAM-622] Disable Java EE 6 tests

Pax Exam 4.x only supports Java EE 7