Update raspbian mdep to match linux mdep.
Add mouse_btn_xxx and mouse_mod_xxx constants.
Rework mdep_mouse implementaitons to return control+shift mouse modifier.
Rename M_xxx to MENU_xxx constants for menus to be more consistent with keykit code constants.
Fix checkmouse to remap unknown mouse buttons to right mouse button(previous check allowed middle button).
Update raspbian mdep to match linux mdep. Add mouse_btn_xxx and mouse_mod_xxx constants. Rework mdep_mouse implementaitons to return control+shift mouse modifier. Rename M_xxx to MENU_xxx constants for menus to be more consistent with keykit code constants. Fix checkmouse to remap unknown mouse buttons to right mouse button(previous check allowed middle button).