Changed pychan font loader to use xml.sax instead of SimpleXMLSerializer.

Fonts are now loaded from files of the following format:

<fonts>
    <font name="pickbelt" type="truetype" size="13" color="255,255,255" source="content/fonts/LinLibertineB.ttf" antialias="True"/>
    <font name="default" type="truetype" size="15" color="68,42,2" source="content/fonts/LinLibertineI.ttf" antialias="True"/>
    <font name="default_bold" type="truetype" size="15" color="68,42,2" source="content/fonts/LinLibertineBI.ttf" antialias="True"/>
</font>