Without this change, the program can not be built on Linux.

Modified qgroundcontrol.pri for Windows VS builds

Fix for last commit

Add of joystick buttons values for manual control

re-enabled terrasync for all operating systems, might produce (non severe) errors on Windows or OS X

stuff was copied that didn't need to be and some things were missing.
For example, the release build couldn't be copied and run on another
computer because the Visual Studio runtime DLLs weren't copied. Their
license allows them to be distributed, so this is fine to do.

added Rascal airplane model for flightgear which also includes a 3D model (from http://flightgear.org/legacy-Downloads/aircraft-2.0.0/)