MTFontIcon 2.0

Big new release with a lot of enhancements and BC breaks. Take a look at the [waffle.io board] to see the progress as well.

- [x] Multiple font support. See #19 and #21.
- [ ] Handle view resizing. See #16.
- [ ] Not fixed configurations file name. See #24.
- [ ] Padding option in configurations. See #23.