this will become the prefered way to access DataEngines rather than
DataEngineManager which exposes implementation details that need to
be manually managed
load requires a containment
fix @since (I could've sworn I did this already..)
rename ContextAction->ContainmentActions
misc. improvements from aaron
no more warnings
qDeleteAll
don't iterate with keys()
svn path=/trunk/KDE/kdelibs/; revision=1012647