#7 Fix drawString font and TrueType bold/italic font mapping

[Donovan Baarda]

This patch is against reportlab 1.17.

It fixes drawstring in renderPDF.py to correctly set
the font and use the canvas' drawString instead of
using addLiteral.

It also fixes font mappings for TrueType fonts to use
the -Bold, -BoldItalic and -Italic fonts so that bold
and italic tags work inside paragraphs, as well as when
referenced directly.

[Donovan Baarda]

drawString and TrueType bold/italic patch