Implementation of Battery Monitor configuration, and addition of AP2ConfigWidget, which automatically handles UAS connections to allow for simpler configuration window code.

Variable calibration procedure text based on the autopilot, stored in files/%autopilot%/general/calibration/description.txt.
Added a new QGCTextLabel type for QGW files, which can display MAV text or hardcoded text.
Added tabular configuration screens based on folder structure inside the files/autopilot/airframe folders

Addressed issue #26. Select System, Plugins and System are disabled when neccessary. Removed style-outdoor-dark.css. Moved the other two .css files and Vera.ttf into files/styles.