Windows build improvements

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.

Fixed Windows compilation and unified serial port baud rate support

This commit unifies the supported baud rates completely across QGC and OSes.

Fixed error (in VS2010) about lacking a return value introduced in 6a55b6cd.

Reverted qportsettings.h changes. Instead we duplicate the OS-specific baud rate settings here within SerialLink.cc.

Modified SerialLink.cc so that it follows the same cross-platform restrictions as the QSerialPort library it relies on.
Windows compilation was broken during 94e91013, which is what prompted this refactoring.

Introduced persistence in RGBDview, needs debugging, fixed a bug in param reading in the simulator, pushed message sender a bit forward, not working yet

Removed outdated MAVLINK v0.9 version as QGC does not work with this version.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.