White space fixes

Add abstract table class

Add code page and Unicode range values in OS2 table

This commits adds code for a legacy feature that still is used
by Microsoft Works and probably many other Windows applications
like Microsoft Word.

Birdfont will set the corresponding bit for a Unicode
range if there is at least one character in that range in the font.
Bits for code pages will be set if there is at least one character
other than the default characters.

Improved TTF generation, character width, gasp table etc.

Add default gasp table (hinting)

Efficient parsing of the kern table

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

mac issues, including a more permissive license for libbirdfont

Subdirectory for open font format tools