This commit add two option to the blenfont library: 1) BLF_FONT_KERNING This enable the kerning information that come with the font, by default this option is disable and still don't have a UI for change. 2) BLF USER_KERNING This allow the user set a kerning value to by apply for every character, by default this option is enable but all the font have a kerning value of zero. Ton I add this option to the style with a default value of 1. Access from: Outliner -> User Preferences -> Style -> FontStyle -> Kerning