[API] moved logging libraries into the Saros core

Change-Id: I6ecc7aeb3f5b5373c62a2ebec267a0d63c535b9f
Reviewed-on: http://saros-build.imp.fu-berlin.de/gerrit/1359
Tested-by: Jenkins CI
Reviewed-by: Stefan Rossbach <srossbach@arcor.de>