[REFACTOR] removed useless MappedList class

Some developers tend to pollute the code base with senseless classes
that are also only used in one class.

Change-Id: I13fedc9733953a81e01d64fec1ad7a813448b6a0
Reviewed-on: http://saros-build.imp.fu-berlin.de/gerrit/1143
Tested-by: Jenkins CI
Reviewed-by: Stefan Rossbach <srossbach@arcor.de>