downgraded version of GEF (3.10 is not accessible in Luna)
first attempt at an implementation of isAffected for instantiation
the idea is to compute a set of resource URIs from given deltas, and for
each subsequent call to isAffected, simply check if the candidate's URI
is in the set
renamed hasMapping/getPreviousMapping in InstantiatorData
solved bug in instantiator
Old entities are no longer contained in a resource set, so #update now
uses the resource set of the new resource
added builder-related classes and modules to inject them
After a lot of poking around, it seems to be the best way of tweaking
the build process to take instantiation into account. Other ways (like
extending the resource description manager's isAffected method) cause
bugs because queuing resources in ClusteringBuildState clears the
ResourceSet. Resources then must be reloaded, which renders the
instantiator's data useless because we use identity equality.
removing the custom description manager
moved instantiator to non-internal package, small changes to data
updated ToBeBuiltComputer (license, import, some code)
correction in builder state, added comments to ToBeBuiltComputer