When adding new SU or PG, tree should stay expanded and new PC should be selected.

[mrmurphy]

http://code.google.com/p/byu-cs340-fall12-issuetracker/issues/detail?id=189&can=1&q=Team%3D5&colspec=ID%20Status%20MergedInto%20Priority%20Phase%20Team%20Owner%20Summary