${PYTHON_DEFAULT_VERSION}, this generates conflicting packages.
- Create symbolic links as PEP 394 [1] suggests. ${PYTHON_DEFAULT_VERSION}
will create python and python${MAJOR_VERSION} links. In current default,
lang/python27 will create: python -> python2 -> python2.7
- Introduce ${PYTHON3_DEFAULT_VERSION}, which will handle bin/python3 link.
At this point, lang/python33 will create python3 -> python3.3
- Minor cleanups
* Trim Makefile headers
* Remove ${OSVERSION} detection for xz, whihc is done by USE_XZ
[1] http://www.python.org/dev/peps/pep-0394/
6e2fa0573b