Log message:
Remove @dirrm entries from PLISTs

Log message:
Simply and speed up buildlink3.mk files and processing.
This changes the buildlink3.mk files to use an include guard for the
recursive include. The use of BUILDLINK_DEPTH, BUILDLINK_DEPENDS,
BUILDLINK_PACKAGES and BUILDLINK_ORDER is handled by a single new
variable BUILDLINK_TREE. Each buildlink3.mk file adds a pair of
enter/exit marker, which can be used to reconstruct the tree and
to determine first level includes. Avoiding := for large variables
(BUILDLINK_ORDER) speeds up parse time as += has linear complexity.
The include guard reduces system time by avoiding reading files over and
over again. For complex packages this reduces both %user and %sys time to
half of the former time.

Log message:
Include pyversion.mk include the protected part of the buildlink3.mk
files, not over and over again.

Log message:
Remove PYBINMODULE. All it did was mark some packages as not available
on some platforms that lacked shared library support in the past. The
list hasn't been maintained at all and the gain is very limited, so just
get rid of it.

Log message:
Update PYTHON_VERSIONS_COMPATIBLE
- assume that Python 2.4 and 2.5 are compatible and allow checking for
fallout.
- remove PYTHON_VERSIONS_COMPATIBLE that are obsoleted by the 2.3+
default. Modify the others to deal with the removals.

Log message:
PYTHON_VERSIONS_ACCEPTED+=25

Log message:
Convert to use PLIST_VARS instead of manually passing "@comment "
through PLIST_SUBST to the plist module.

Log message:
Never use setuptools to make builds consistent independent of whether
py-setuptools is present or not.