State render groups settings

Add tabs and groups to the settings dialog

In the groups tab:
* Add selectable options to nest apicalls
* Add display controls for Debug marker groups
* Update tree display dynamically

The default is the current tree display and won't look any different

This addresses item 1) from issue #161
> 1) Add a way to toggle between modes so that users can easily just see the draw calls without other clutter and clicking - perhaps a combo box so that we can easily add more hierarchy methods without consuming too much toolbar space?

Except instead of using comboboxes, use checkboxes in a scrollable groupbox
![vogl-group-settingsa png](https://cloud.githubusercontent.com/assets/6090880/5056387/754bb718-6c36-11e4-93bd-d835d28a5206.png)