[INTERNAL] changed IPN projectMapping parameter

it now requires a id=>project mapping instead of a id=>project-name
mapping.

Change-Id: Ib4f825c2bef3d537120ff32810ba38b7731d99d9
Reviewed-on: http://saros-build.imp.fu-berlin.de/gerrit/1927
Tested-by: Jenkins CI
Reviewed-by: Stefan Rossbach <srossbach@arcor.de>