Basic support for a generic "clone item" button. (Still need to implement clone schema). This creates an exact copy of the currently selected item, within the same context.
Refresh now works. (Clear the treeview prior to loading all models).
Fixed a bug in connecting column to level: if the relationship was dropped on the level header, we would get a runtime exception. Now, dropping on the header of the level behaves as if it was dropped on the key column of te level (i.e. it sets the column attribute of the Level element).
Implemented clone of the document (from within the schema editor). We can now effortlessly make as many copies of a schema as we like.
Can now delete relationships between level and hierarchy from within the hierarchy diagram. Still have to implement that for tables.
Prevent adding the clone button multiple times to the editor's toolbar (this happend in the shared dimension editor).
Use the view icon when we have objects of type system_view (i.e. MySQL Information schema tables).