White space fixes

Rename XML namespace

Merge branch 'master' of gitorious.org:birdfont/birdfont

Replace libxml2 with libbirdxml
This commit does also remove the deprecated ffi support. BirdFont 1.4
or older can be used to convert ffi files to the new bf font format.

Speed optimizations of TTF export code
Exporting kerning pairs is now more than a thousand times faster for big
fonts.

Kerning by classes
This implementation uses the PairPosFormat1 to store kerning values in
TTF files and has a new kerning display that allows the user to define
kerning classes.

Some code to do PairPosFormat2 is included as well but it seems like
the PairPosFormat1 is the better solution.

Merge branch 'master' of gitorious.org:birdfont/birdfont

mac issues, including a more permissive license for libbirdfont

rename supplement namespace to birdfont

new directory structure