Change so mission view is default instead of unconnected, fixing a bug causing misloading of tool widgets

Additions for View navigation, including saving dockwidget locations and status. Also added remembering of "Advanced Mode" between restarts of QGC

Changes for the new "View" navigation, and fixes to get most of the dockwidgets working with the new view system

view, rather than having universal dock widgets.

Implementation of 6DOF 3DMouse input (Windows only). Not tested yet.

Pushed HIL with X-plane to being close to operational. Receiving from X-Plane  implemented, sending to it is prepared. Needs an iteration of onboard SW first

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.

Removed some dead code.
Added more valueChanged() signals to account for every data type. This moves the conversion over into the valueChanged receivers, which while it will require more slot-functions, makes it easier to add more code as any necessary conversion is done internally to the slot and so the signaler doesn't need to know the details.
I also added some more details on the types of units expected by valueChanged().