Merge pull request #1 from openframeworks/master

与官方同步
Add to ofxgui ofxDropDownList, ofxQuadWarp, ofxContent.
解决ofxml不能正确加载中文的问题, 因为of内部也需要用ofxSonovoUtil的转换方法,所以就直接放到了ofUtil里,并且函数名字由ofx变成了of.
添加ofxFontStash子模块.
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
modify ofxContent & ofxDropDownList & ofxQuadWarp
Increase support for fontStash features
提交.gitmodules.
update .gitmodules
Merge branch 'sonovo-ofxGui' of github.com:yty/openFrameworks into sonovo-ofxGui

Conflicts:
	libs/openFrameworks/utils/ofXml.cpp
	libs/openFrameworks/utils/ofXml.h
Modify ofxBaseGui & ofxDropDownList
Merge branch 'sonovo-ofxGui' of github.com:yty/openFrameworks into sonovo-ofxGui