Merge pull request #1 from openframeworks/master

与官方同步
Add to ofxgui ofxDropDownList, ofxQuadWarp, ofxContent.
fix ofxGui.h
Modify the ofxDropDownList the return value of the problem.
update ofxgui example
modify ofxDropDownList adaptive global size & click menu trigger a repeat
sync sonovo-master
Merge branch 'master' of github.com:yty/openFrameworks into sonovo-ofxGui
Merge branch 'sonovo-ofxGui' of github.com:yty/openFrameworks into sonovo-ofxGui
add to ofxgui ofxDropDownList, ofxQuadWarp, ofxContent.
add newofxGuiExample.
Merge branch 'sonovo-master' of github.com:yty/openFrameworks into sonovo-master
提交.gitmodules.