[INTERNAL] cleaned up transfer mode states

Some states are not relevant to the network layer and were just used for
logging.

Change-Id: Ib645e6142970006015d643c3321f8c731e1695b5
Reviewed-on: http://saros-build.imp.fu-berlin.de/gerrit/1321
Tested-by: Jenkins CI
Reviewed-by: Stefan Rossbach <srossbach@arcor.de>