New upward relationship modified
add ITraceabilityStorageListener.java to handle event on ITraceabilityStorage.java
Fixes on sspecific part of Reachable.java
add a Reachable.java handler for String/integer/URI
git ignore
Merge branch 'develop'

Conflicts:
	plugins/org.eclipse.reqcycle.traceability/src/org/eclipse/reqcycle/traceability/exceptions/EngineException.java