Allow all keybindings for all peripherials

[zerO_crash]

As it stands right now, there are functions which you cannot bind to e.g. a mouse (F-10 map, +++). I see no reason why this would be blocked to begin with. If one has a multi-button mouse, it's logical to want to put some of the "basic" functions on the mouse. I ask for a possibility to bind all bindings to any unit (possibly except axes - makes no practical sense).

 

Thanks!