Compress notifications about new mouse/keyboard.

When resuming from suspend, I get 5 "new pointer" and 5 "new keyboard" events (on a laptop with USB mouse/keyboard, but also stuff like "Thinkpad Extra Buttons" adds more notifications than one would expect)

KGlobalAccelImpl::x11MappingNotify is still called 15 times, but that's better than 145 times...

"new pointer" notifications end up calling kcminit mouse, better also compress that.