priority events + ofEventMarkAttended + attended and priority for ofxGui
Merge branch 'develop' into feature-priorityAttendedEvents

Conflicts:
	libs/openFrameworks/events/ofEventUtils.h
ofDelegate + ofxGui with return value
Merge branch 'develop' of github.com:openframeworks/openFrameworks into feature-priorityAttendedEvents
iphone video player: add frame based position
fix getCurrentFrame
urlFileDownloader: progress event + example
Merge branch 'feature-priorityAttendedEvents' into arturodevelop
Merge branch 'feature-URLProgress' into arturodevelop
Merge branch 'feature-iPhonePlayerFrame' into arturodevelop
Merge branch 'arturodevelop' of https://github.com/arturoc/openFrameworks into feature-androidvideo