Use TTF_RenderUTF8_Solid instead of TTF_RenderText_Solid

Pebble recognizes and displays UTF8 so PebbleLocalSim should do too.

Turns this:
![localsim-ascii](https://f.cloud.github.com/assets/304352/1792473/1cabba34-69a0-11e3-905c-2bb36d811690.png)

Into this:
![localsim-unicode](https://f.cloud.github.com/assets/304352/1792475/24af90d4-69a0-11e3-864b-d61d8662958d.png)