DO NOT MERGE: adding drop-test support for karaf

- added empty test-common bundle for test logic
- test logic will be pulled in later
- drop test logic pulled up to test-common
- fixed notificationListener registration
- added karaf command implementation (drop-test, dropAllPackets)
- added dropAllPacketsRpc
- fixed features xml format

Change-Id: I06249f4671121e89a7de1a8003feef8fe0b2fca1
Signed-off-by: Michal Rehak <mirehak@cisco.com>
Merge "DO NOT MERGE: adding drop-test support for karaf"