Fix #623 - Add Quality selection options to ConfigTool for Audio/Video output

Fix #623 

Tasks:
- [x] Add ComboBoxes for quality selection
- [ ] Have ComboBox selection set current bitrate for current plugin based on resolution
- [ ] Have ComboBox selection set bitrate for all plugins unless/until overridden
- [ ] Recompute video bitrate based on quality and resolution on record?
- [ ] Add config support for Ogg Icecast
- [ ] Add config support for WebM Output
- [ ] Disable config button and quality comboboxes when RAW Output is selected

Screen:
![quality selection](https://cloud.githubusercontent.com/assets/5759678/4958137/1ff74286-66ab-11e4-85b9-a0fe68cb225b.png)