[Pythonmac-SIG] add other Python distros to the downloads page?

[Bill Janssen]

All right, I've added a wiki page (have I mentioned how much I dislike
wiki markup syntax?  oh, well...) called PythonDistributionsForMac.
Everybody, please review if you care, and fix as necessary.  Trent,
you'll want to add a fuller description of ActivePython.  I'll put a
link to this page at the bottom of the downloads page.

Bill