Switch to new Karaf version

[wiiitek]

Following steps should help upgrading to newest Karaf framework

Phase A:

1. Remove start level from aet-features.xml file (so that default is used).
2. Group dependencies into sub-features
3. Make aet-features.xml fle a filtered resource so that we could change it easily in maven lifecycle.
4. For some dependencies versions (the easy ones) that are in aet-features.xml make them to be read from project properties so that same versions are used as Maven dependencies
5. Validate and update not-so-obvious dependencies, remove them if it is possible

Phase B:

Upgrade those dependencies that don't work on new Karaf and swith to new Karaf instance. (It might be easier to switch to ActiveMQ v 5.15.x instead of resolving Spring dependencies for ActiveMQ 5.13.1.)

[wiiitek]

Merged with #204