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

Put libraries into one libs directory under qgroundcontrol. Changed the neccessary files with references to those libraries.

Replaced the autopilot-specific inclusion of MAVLink to be more generic. Now if you have no actual QGC modifications to make and just want your messages to be available for viewing/logging you can just create the user_config.pri file and override MAVLINK_CONF.

Corrected the Windows Visual Studio compilation so that release builds no longer have a console or debugging macros while the debug builds have both.
Fixed indentation across all build scripts (.pro/.pri) to be 4-spaces and consistent.
Updated the README with proper Visual Studio compilation instructions for both VS2010 and VS2008.

Added remote OpenGL drawing in 3D view. Any external application can draw to the 3D view via the protobuf implementation of GLOverlay messages.

Removed outdated MAVLINK v0.9 version as QGC does not work with this version. Added feature to import COLLADA terrain model and visualize model in 3D view.

Mission Plan Widget: Added support for MAV_CMD_DO_SEARCH custom pixhawk commands, fixed some tooltip bugs.

Remake of "editable" mission elements is now complete and usable. Missing widgets for Takeoff and Land will be added soon.

Added visualization of obstacles. Fixed relative font path issue in 3D widgets by using QFont within osgText::Font instead of using static font filename.