ezgui extension

Hello Imkira :)

This is my first fork so I'm a little jumpy about what to do from here. Briefly I'm going to describe you the problem and the solution that head me to this. I required some kind of mechanism to support japanese and chinese characters into a game's ui that is completely made with ezgui. I tried with the ezgui "font atlas" system but that is just to heavy to be supported by mobile devices. There is where I found your sysfont solution (that actually saved my life). Unfortunately, due the requirements I cannot replace the ezgui labels, instead of that, I must conserve them for english (due the font effects as stroke and shadows) and use your sysfont text for japanese and chinese localization texts.

So, that's it. The ezgui plugin is not included and additionally, I used the unity tools for unit testing (nunit and nsubstitute). Those are free so I didn't ignored the included folder. 

Thanks a lot for your plugin and thanks in advance for your time. I don't know if this worths to be part of the master branch or should I leave it where it is now.


Have a nice day :)