Evas: Fixed many compilation warnings.

Evas: Fixed many compilation warnings.
1. Fixed evas_common_encoding_utf8 functions to get char * instead of unsigned char * and return Eina_Unicode instead of int.
2. Removed a couple of unused variables.
3. Removed deprecated evas_common_font_utf8* functions.

git-svn-id: svn+ssh://svn.enlightenment.org/var/svn/e/trunk/evas@51200 7cbeb6ba-43b4-40fd-8cce-4c39aea84d33