Changed SelectionProcessor to receive Collection<?> instead of ISelection as the input selection.
This is because of Eclipse bug #254570 which causes StructuredSelection to be unusable as a DB query
identity.
Also changed GE mouse doubleclick handlers to pass the direct contents of the GE's selection to the
double click handlers instead of the data behind TreeItem.getData(). This makes double click handling
uniform with respect to other selection testing, which is performed in EditorAdapter implementations
for example.
git-svn-id: https://www.simantics.org/svn/simantics/sysdyn/trunk@16942
ac1ea38d-2e2b-0410-8846-
a27921b304fc