ofTrueTypeFont support for iso8859-1 on utf-8 encoded files

ofTrueTypeFont as it is right now has support for all the characters in iso8859-1 if the flag bFullCharacterSet is set to true when loading, which can render all the extended characters in the latin alphabet like ñàäáâç... 

the problem is that most IDEs use utf-8 encoding by default so when writing this characters in strings in the code or text files they fail to render because the encoding freetype is expecting is iso8859-1.

this converts utf-8 to iso8859-1 which solves the problem of rendering special characters for the latin alphabet. might be good to test in code from other ide's in case the default encoding is not utf-8