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 It doesn't make too much of a difference in terms of actual recording quality, but for the log message and in the configure dialog, it looks better if the video bitrate is something like 3800 instead of 3782. What do you think? Should I keep it or remove the rounding?