input: allow to destroy bindings in their handler
input: allow to destroy bindings in their handler

use wl_list_for_each_safe to iterate on the bindings list when
firing them, this way a binding can safely be destroyed in its
function handler.

Acked-by: Pekka Paalanen <0f6ae7001e34c37b02fb2c1c2573ddf8f442136a@collabora.co.uk>

eyolfson/weston,Fantu/compositor-spice,krezovic/weston,jonnylamb/weston,sir-murray/weston,Fantu/compositor-spice,giucam/weston,Gnurou/weston,Fantu/compositor-spice,xorgy/weston,udoprog/weston,jonnylamb/weston,eyolfson/weston,udoprog/weston,mchalupa/weston,xorgy/weston,krezovic/weston,mchalupa/weston,sir-murray/weston,Tarnyko/weston-xdg_surface_present,kwm81/weston,giucam/weston,kwm81/weston,Tarnyko/weston-xdg_surface_present,Gnurou/weston