#46 io::controller

[Bryan Wagstaff]

io::controller objects should call cull in their
destructor if the programmer did not.

This would solve the problem of still being attached
to a keyboard or other device at exit, causing a crash
rather than graceful exit.

This becomes important when an error condition causes
an abnormal shutdown.

cull should still be present because developers may
wish to attach and detach different controllers at a
whim.

bryanw.