Further refactoring:

* Add undecorate-display! and decorate-display! fns
* Add active? and inactive? fns
* Pull out new stop fn
* Allow title of window to be specified
* Rename start-run-thread to start
* Separate public and private API
Merge remote-tracking branch 'origin/master' into sam

Conflicts:
	src/shadertone/core.clj
Add support for fullscreen and pseudo-fullscreen shader displays.
Remove debug statement
Merge pull request #8 from samaaron/sam

Further refactoring: