Fixing 'New Project'.
Fixed crazy naming of click handlers.
Merge branch 'NewProjectFix' into UndoRedo
Unified 'Selection' (IController.Selection).
This is in preparation for multi-item property editing.
Note: Technically it already sets PropertyGrid.SelectedItems to the multi-item selection, but its useless because Processor and Importer properties are not recognized as the same between items (even when they are).