start linking in libfreetype to get line gap / leading info from
fonts.
use freetype to load a font ready for extracting leading.
get linegap via freetype
refactor type face code to use list of type_face structs, and
simplify font style attribute parsing etc.
correct bugs following type face refactor.
adjust type face settings for book title lines.
use type_face structure in pieces
fix small caps
implement right and centre alignment. some bugs remain.
fix alignment behaviour
adjust default type face styles for vers numbers and smallcaps
size in book title.
fix calculation of linegap.
fix placement of booktab text.
fix various issues with outputting lines.
get rid of blank first page.
fix some text alignment bugs
fix centring of text when centred text wraps to multiple lines.