[[ CoreText ]] Added support custom font loading.
[[ CoreText ]] Updated font creation routines in an effort to remove warning on 10.9.
[[ CoreText ]] Updated text drawing to take into account extra width required by italic fonts.
[[ CoreText ]] Updated docs note to add info about symbol fonts.
Merge branch 'feature-coretext' of https://github.com/runrevmichael/livecode into feature-coretext