OB-TraitsIntegration and tree navigation of Traits

If someone is interested, there is a browser with tree navigation.

Load packages:

• OmniBrowser-jk.398
• OB-Standard-jk.312
• OB-TraitsIntegration-jk.38

from http://www.squeaksource.com/JKExperiments.html and try

• OBTraitsBrowser open. "or"
• OBTraitsBrowser openOn: ClassDescription

How is it done:

• OBTreeColumn breaks 1 to 1 relation between OBColumn and OBFan.
• OBTreeFan holds all necessary OBFans.
• You can define #treeNavigate for an OBMetaEdge.
  
• See OBTraitMetagraphBuilder>>populateTraitFilterInTree.

TODO:

1. Handle switches.
2. Decide how to integrate OBTreeColumn to OmniBrowser. I think an OBMetaNode should decide what be used as next column (pane). Now it is done by used OBColumnPane.
3. Write unit tests.
4. Bugfixes (There is at least one which freezes a image. Do not switch between class categories if a subtree item is selected.).