[KARAF-2888] Fix IllegalStateException if a bundle has been manually installed and is later requested by a feature
[KARAF-2911] Remove resolver and region services from subsystems feature (they are provided by features.core bundle)
Remove service.guard from framework-security feature, it has its own service-security feature
[KARAF-2923] Make sure bundles part of a conditional are only used to solve optional dependencies if the conditional itself is satisfied
[KARAF-2942] Require JDK7 for Karaf 4.x
[KARAF-2942] Switch features/core to JDK 7