Send dummy events each second to prevent excessive memory use (inspired by xnyhps)

Send dummy events each second to prevent excessive memory use (inspired by xnyhps)

I'm not that good in Mac programming it seems as I can't figure out why
doesn't the memory being allocated by frequent NSNewBitmapBackingStore
(system internal) calls being freed even if I wrap the code into
@autoreleasepool explicitly. Disabling animations does slow it down but
not stop. This commit is certainly a dirty fix but it seems to work in
my case and I hope it helps a few other people while we wait for a
proper solution.