ofEvent: fix for void events. Closes #1166
Merge branch 'develop' of github.com:openframeworks/openFrameworks into develop
Merge branch 'develop' of github.com:openframeworks/openFrameworks into develop
adds ofMatrixMode
load/mult matrices methods for cairo
ofCamera totally independent from openGL
fixed broken hole detection in CV contour finder, ofxCvBlob.hole bool now works correctly; updated openCVExample to denote detected holes with some text to make checking this easier in the future; also updated sprintf in example to use a stringstream
new events example. simpleEventsExample
Add new version defines, update ofGetVersionInfo().

New defines are OF_VERSION_MAJOR,  OF_VERSION_MINOR, OF_VERSION_PATCH. Old define OF_VERSION is removed because of incompatibility with new system (old MINOR is new MAJOR). This way any code that uses it fails to compile instead of silently making wrong decisions.
Add info about SemVer to the global Readme.

This closes the OF-repo side of #1706.
Remove the prefix text in ofGetVersionInfo().

This removes the unnecessary text which should be added at the user side anyway, and makes it easier for people to parse the OF version string, to compare against for compatibility etc. 
ofGetVersionString() would be a better name, but it's not worth changing the API for this, imo.
changed circle to Circle. changed listener methods names.
Merge branch 'develop' into feature-VoidEvent

Conflicts:
	libs/openFrameworks/events/ofEventUtils.h
Merge pull request #1398 from arturoc/feature-VoidEvent

Feature void event
Merge pull request #1811 from bilderbuchi/feature-semver-changes

Semver changes
included support for PREFER_RGB_OVER_YUV and PREFER_NON_COMPRESSED defines when framerate is specified
Update CONTRIBUTING.md
cleaned ofEasyCam.h and added few getters to ofCamera
Merge pull request #1845 from roymacdonald/ofCamsAdditions

new getters in ofCamera
Merge pull request #1842 from timscaffidi/bugfix_gstVideoGrabber_formatType

included support for PREFER_RGB_OVER_YUV and PREFER_NON_COMPRESSED ...
Merge pull request #1799 from roymacdonald/feature-simpleEventExample

new events example. simpleEventsExample
ofCamera: remove dependencies with glu