Cleaned the error messages and removed the random exit(-1).

Change-Id: I26948a3ca397660794cded2ed09af62229d456d3
Minor bugfixes and interface cleanups.

Change-Id: I6a3329298db3f98ccdad62c8225ea54349f68e30
Move BackgroundWidget to DisplayCluster application.

Change-Id: If282316c6065c53dcb6db527d7fc47f37ebce0b4