Implementing operations dispatcher.
Merge branch 'transformation-blackbox' of https://github.com/ooti2013/qvto into transformation-blackbox

Conflicts:
	examples/org.eclipse.qvto.examples.pivot.trad2pivot.java/src/org/eclipse/qvto/examples/pivot/trad2pivot/java/QVTo2PivotQVTo/Dispatcher.java