Patch Set 1: I would prefer that you didn't submit this

Looks much better than the previous one with two trees :-)

Found the following problems:
- can't open compare editor on deleted files (works on added and modified files)

these features would be nice to add in future changes:
-could we add the following toggle filters: "show added", "show deleted", "show modified"
- would be nice to use navigation buttons (up, down arrow) for jumping from one file to the next (can this be done with arrow keys on the keyboard?)
- would be nice to have a way to expand a subnode recursively so that I don't have to click 10 times for a 10 level deep hierarchy.