Fix violations of 4.2.2 Function Definitions and 4.2.3 Control
Statements.
Set the minimum CMake version required to build to 3.1.
Removed the Visual Studio solution and project files.
Added full support for using a 3Dconnexion device in PCB_EDIT_FRAME. Commands are exported and can be assigned to 3D mouse buttons. Any limitations to the functionality are limitations of the installed 3Dconnexion driver for the device and OS.
Use build option KICAD_USE_3DCONNEXION (default = ON) to control whether the SpaceMouse support is compiled into the solution.