#1 fonttools: add support of bitmap

[Serge Vakulenko]

Metatype does not generate hints for Truetype fonts,
and will not in near future. Without hinting, fonts
look ugly in low point sizes.

We could live without hinting, using precomputed
bitmaps for small point sizes. Unfortunately,
fonttools which are used to create Truetype fonts from
XML sources, do not support EBDT and EBLC tables,
which are needed for bitmap fonts.

Adding support for EBDT and EBLC tables requires good
knowledge of TrueType (OpenType) file format. OpenType
specification is available as
http://www.microsoft.com/typography/otspec/default.htm
.