ENABLE_3DCONNEXION_DEVICES - 1st installment of support for 3Dconnexion devices

Implemented using hidapi library (https://github.com/libusb/hidapi) and https://github.com/koenieee/CrossplatformSpacemouseDriver/tree/master/SpaceMouseDriver as reference

Unsolved issues:

- When manipulating the SpaceNavigator wxWidgets generates a mouse wheel event that needs to be filtered out

- wxWidgets does not detect devices being connected/disconnected to the pc

- Current state forces a continuous rendering

- Current state misses dependence on camera zoom

- Non intuitive movement limits

- Translation and rotation speed factors are hardcoded

- Number of device buttons hardcoded

src/slic3r/GUI/MainFrame.cpp

@@ -24,6 +24,9 @@
 #include "PrintHostDialogs.hpp"
 #include "wxExtensions.hpp"
 #include "GUI_ObjectList.hpp"
+#if ENABLE_3DCONNEXION_DEVICES
+#include "Mouse3DController.hpp"
+#endif // ENABLE_3DCONNEXION_DEVICES
 #include "I18N.hpp"
 
 #include <fstream>
@@ -108,6 +111,10 @@ DPIFrame(NULL, wxID_ANY, "", wxDefaultPosition, wxDefaultSize, wxDEFAULT_FRAME_S
         }
         
         if(m_plater) m_plater->stop_jobs();
+#if ENABLE_3DCONNEXION_DEVICES
+        if (m_plater != nullptr)
+            m_plater->get_mouse3d_controller().set_canvas(nullptr);
+#endif // ENABLE_3DCONNEXION_DEVICES
 
         // Weird things happen as the Paint messages are floating around the windows being destructed.
         // Avoid the Paint messages by hiding the main window.