Scrollbars now maintain position slightly when the tree is refreshed in anyway (Generation change, spacing change, etc.) but NOT when a new parent node is selected. Also resolves an undocumented issue where switching to Active tree then back to any other tree would not work. Code cleanup as well.
Merge pull request #44 from Mctalian/patch_6

Resolves Issue #6: Scrollbars now maintain a position when tree is refreshed.