Fix #476 Auto-detect language on fresh launch

Freeseer will now try to use the appropriate translation if it exists
for the user's system language. It does this by detecting the user's
locale and searching for a matching translation. The US English
translation will be used if no matching translation exists.
Added ComboBox for Quality selection
Ogg Output settings now modified by quality selection
Add Audio/Video quality saving to config. All output plugins except WebM now affected.
Added bitrate/quality customization to Ogg Icecast.
Some code changes
Added 'configurable' variable to output plugins class