Use PYTHON_VER instead of PYPY_VER for directory suffix.

While attempting to integrate pypy into bsd.python.mk it became apparent that
it is easiest if the implementation version was not used but the python version
implemented.

Based on that motivation, switch to using PYTHON_VER suffix.
Tidy up patches.
Correctly substitute %%PYTHON_VER%%, not %%PYPY_VER%%.
Use PYTHON_VER for binary suffix in pkg-plist.