Use notifications for connection registry instead of polling.
override CGraphicsUtil.draw9pcsBackground with native impl
set maxDifferent to the correct number of differing pixels
Merge pull request #395 from mykmelez/native-CGraphicsUtil-draw9pcsBackground

override CGraphicsUtil.draw9pcsBackground with native impl (fixes #317)
Merge pull request #390 from brendandahl/registry

Use notifications for connection registry instead of polling.