Ansible is now available to install via pip

I had received enough requests for ansible to be installable via pip
that it is now uploaded to PyPi. A cursory test of installing it in
virtualenv seems to imply it looks ok.

Note that the pip binary tries to install PyCrypto (fireball mode)
which is *optional* and some other things, so this is probably not for
everyone, and I still recommend running
it from checkout or installing via RPM/apt/etc package if you don't
care about those things.

--Michael