Python 2.6 update with portmaster

[Wesley Shields]

Here's a patch[1] that allows you to use portmaster when doing the python
upgrade. I intend to commit this tomorrow morning unless someone speaks
up. I'll also be adding the instructions to the UPDATING entry.

Once applied you should be able to use:

cd /usr/ports/lang/python && make upgrade-site-packages -DUSE_PORTMASTER

It will be quite slow compared to using pkg_which (the normal method) so
be patient. I've used this patch to upgrade one lightly used machine and
I know at least one other person has survived an upgrade of a machine
with over 1000 ports installed.

[1]: http://people.freebsd.org/~wxs/python26-portmaster.diff

-- WXS