CallbackQuitEvent
final changes QuitEvent
Merge branch 'experimental-v0.8.0' into callback
update CHANGES.txt
Update CHANGES.md
Update callback_functions.py
example
Merge branch 'callback' of github.com:expyriment/expyriment into callback

Conflicts:
	expyriment/callback_functions.py
BUG: mouse.wait_motion
Merge pull request #42 from expyriment/callback

Callback