Additional output formats C# and Xamarin

[rhegner]

Xamarin 4 has improved support for icon fonts, which makes dealing with scalable icons in Xamarin much easier.

I modified icon-font-generator to generate two additional outputs:

• A C# class containing the unicode constants
• A Xamarin ResourceDictionary containing the unicode constants

icon-font-generator is a really helpful tool, and it would be nice if it supported these additional output formats out of the box.