Add checks, rules and variables to the build system for docwriter.
* Running `make' will warn if Python/PIP/docwriter are not available.
* Running `make refdoc' will generate static documentation site on the
current Python environment.
* Running `make refdoc-venv' will generate static documentation site
using a virtual environment, using the pip package `virtualenv'.
direct computations with 16.16 values instead of sub-divisions.
It is now slower, but proves a point :-)
* src/raster/ftraster.c, src/smooth/ftgrays.c, src/base/ftbbox.c :
fixed the bezier stack depths..
* src/base/ftcalc.c (FT_MulFix): minor rounding fix
* builds/beos : added BeOS-specific files to the old build system
(no changes were necessary to support BeOS in the Jamfile though)