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

Fix #623. Easier configuration for output quality of video and audio by using a combo box to select. The bitrate determined for video will be based on the system resolution.

Tasks:
- [x] Add ComboBoxes for quality selection
- [x] Have ComboBox selection set qualities for Ogg Output
- [x] Have ComboBox selection set qualities for all plugins
- [x] Save ComboBox selection in profile and whether it should be used or has been overridden by manual quality entry
- [ ] Recompute video bitrate based on quality and resolution on record if "No Scaling"
- [x] Add config support for Ogg Icecast
- [ ] Disable config button and quality comboboxes when RAW or WebM Output is selected
- [ ] Support scaling
- [ ] Support non-screen inputs

Screen:
![quality selection](https://cloud.githubusercontent.com/assets/5759678/4958137/1ff74286-66ab-11e4-85b9-a0fe68cb225b.png)
@mtomwing Yeah I had realized this issue. Hadn't gotten around to putting it in the task list. Also need to deal with scaling for screen recording since the resolution won't matter in that case.