otfautohint: Dependency on specific glyphs names

[khaledhosny]

Some parts of the autohinter behave different based on glyph names, but this assumes glyphs are always named after a specific name list which might not always be true. We probably should collect these glyph names, map them to code points and always pass to the autohinter the names it expects based on the code points associated with the glyphs.