[INTERNAL] deprecated BlockingProgressMonitor

I failed to see the proof of the corresponding thesis that states that
there exists Eclipse API methods that takes and IProgessMonitor (those
should report .. should'n they ?) but (according to the thesis) returns
immediately. If this holds true than those classes that implements
the interfaces ARE BROKEN but not the progress reporting API/Pattern of
Eclipse !

Change-Id: I7e76c93589114b3f0633254909ef918094347fa4
Reviewed-on: http://saros-build.imp.fu-berlin.de/gerrit/1274
Tested-by: Jenkins CI
Reviewed-by: Stefan Rossbach <srossbach@arcor.de>