Improved Google Earth interface, clearing trails works, switching views works (but is not yet perfect), switching editing mode on/off works

Working on better simulation implementation, fixed a bug where the port handle was not fully released

Added not yet working version of logging / log replay, fixed ALL bugs in main window, enabled full persistence in main window and serial link.

Significantly bugfixed persistence and link adding/removal. Not yet fully there, but getting closer to release

Added to 3D view user switching between local and global coordinate system. Fixed bug in WaypointView: new instance used to assume frame is global.

Changed status message in qgroundcontrol.pro, fixed compile error in class Freenect (void* did not work)

Still need to add uas connections. New osgwidget inherits from
qgraphicsview to expose more functionality to qt. Map3d.ui contains
the graphics view and some buttons. Currently runs yahoo_heightfield
by default. Make sure you run qgroundcontrol fromt the top dir or
it will seg fault, :-). I'll add some error handling soon.