A couple of improvements


Hey EmmittJ,

I've a made a couple of changes there:
- reworked UI a bit
- highlight attributes on right-click
- fixed crash with empty tree sreenshoting

Feel free to merge them.

KR,
Aliaksei

![closed](https://cloud.githubusercontent.com/assets/1394349/4045463/06d10022-2d2a-11e4-8170-6d028b2d9159.png)
![open](https://cloud.githubusercontent.com/assets/1394349/4045464/06d888d8-2d2a-11e4-8e67-84b1c715f534.png)