Allow OpenWithMenuContribution to support multiple selection input
Currently OpenWithMenuContribution will immediately dismiss any inputs that are not single selections.
In some cases it would be useful to support opening editors or views based on multi-selections.
To avoid denial of service problems, it is best to have some practical limit for the size of the input given to:
final EditorAdapter[] editorAdapters = EditorRegistry.getInstance().getAdaptersFor(graph, r);
in OpenWithMenuContribution
. Otherwise the checking done by editor adapters can become really heavy, if many implementations actually start checking multi-selections instead of just immediately discarding them based on the selection cardinality.
Edited by Tuukka Lehtonen