Don't sleep in the event thread

The person who wrote this seemed to misunderstand how XPending and
XNextEvent actually work. XNextEvent will wait in poll if there's
no event yet, meaning that we don't need to sleep after we process
all the events; the kernel will sleep for us.

This changes indentation, so view with -w or a similar feature to
understand what's actually changed here.
Merge pull request #896 from magcius/event-thread-bozo

Don't sleep in the event thread