[REFACTOR] renamed sendTo* methods in the ITransmitter interface

Renamed those methods to better reflect their purpose.

Change-Id: I69f828bf74637be1926ba987a3221caf868912f7
Reviewed-on: http://saros-build.imp.fu-berlin.de/gerrit/967
Tested-by: Jenkins CI
Reviewed-by: Stefan Rossbach <srossbach@arcor.de>