[REFACTOR] extracted inner classes of RemoteProgressManager

Put the whole stuff into the new monitoring.remote package and fixed
also concurrency issues.

Change-Id: Id8e38836fa1c0e8b3504769da1161a0cfcf07194
Reviewed-on: http://saros-build.imp.fu-berlin.de/gerrit/1667
Tested-by: Jenkins-Eclipse QA
Tested-by: Jenkins CI
Reviewed-by: Stefan Rossbach <srossbach@arcor.de>