Removed OpenGL dependency in HUD, merged in HUD from Soren Kuula and config changes from Michael Carpenter

Added multi-UAS support to QGCRGBDView. Fixed display timeout issue on computer for which data source is not time-synchronized.

Improved line chart, brought back movement on HUD (but still looks somewhat wrong on the dials). Fixed logging for ground time mode

Substantially bugfixed and improved deactivation/activation and persistence of widgets. A lot of testing of Google Earth view, only minor improvements

Fixed initial startup bugs, cleaned up the activation-deactivation of update timers. Added initial instructions for new users.

Cleaned up and commented major code parts. Refactoring HDD and HSI widgets to support QGraphicsView drag-and-drop, tested multi-MAV support more intensely, currently adding the system coloring to all widgets

Improved runtime performance, currently hunting down a bug where the whole application gets repainted although only parts of it are refreshed