[REFACTOR] moved Compatibility class to its own class file

Change-Id: I172d645201a52f2031554f5d1b5b61e33c8849e9
Reviewed-on: http://saros-build.imp.fu-berlin.de/gerrit/1275
Tested-by: Jenkins CI
Reviewed-by: Stefan Rossbach <srossbach@arcor.de>