Fixes #4817 Found that Tree wasnt implenenting the full notification API for onSet(), implemented it to allow _updateItemClasses to remove old class names prior to adding new ones.
Fixes #4817
Found that Tree wasnt implenenting the full notification API for onSet(), implemented it to allow _updateItemClasses to remove old class names prior to adding new ones.

git-svn-id: 674a2d6b1e32e53f607eb824547723f32280967e@11033 560b804f-0ae3-0310-86f3-f6aa0a117693

redaktor/deliteful