ports/133081: Fix PYEASYINSTALL_ARCHDEP=yes packages

[Chris Rees]

Hi all again,

After much grinding of teeth, I have discovered that easy_install
completely ignores the envar _PYTHON_HOST_PLATFORM.

I also discovered that the only thing it really did was add the egg to
%%PYTHON_SITELIBDIR%%/easy-install.pth, so I wrote some sed and ed
magic to replace it.

This patch now fixes the problem in
http://www.freebsd.org/cgi/query-pr.cgi?pr=ports/133081.

I've tested it and it works, and all the affected ports pass tinderbox.

Any comments before I commit?

http://www.bayofrum.net/~crees/patches/python-filthy2.diff

Chris