either because they themselves are not ready or because a
dependency isn't. This is annotated by
PYTHON_VERSIONS_INCOMPATIBLE= 33 # not yet ported as of x.y.z
or
PYTHON_VERSIONS_INCOMPATIBLE= 33 # py-foo, py-bar
respectively, please use the same style for other packages,
and check during updates.
Use versioned_dependencies.mk where applicable.
Use REPLACE_PYTHON instead of handcoded alternatives, where applicable.
Reorder Makefile sections into standard order, where applicable.
Remove PYTHON_VERSIONS_INCLUDE_3X lines since that will be default
with the next commit.
Whitespace cleanups and other nits corrected, where necessary.
Support is included for the following formats (RGB colorspace only;
conversion to/from HSL can be handled by the ``colorsys`` module in
the Python standard library):
* Specification-defined color names
* Six-digit hexadecimal
* Three-digit hexadecimal
* Integer rgb() triplet
* Percentage rgb() triplet
