Remove everything related to os x expert package

We decided to no longer ship expert packages for OS X because they're a
lot of trouble to keep maintained and confuse users. For those who want
a tor on OS X without Vidalia, macports is a fine option. Alternatively,
building from source is easy, too.

The polipo stuff that is still required for the Vidalia bundle build can
now be found in the torbrowser repository,
git://git.torproject.org/torbrowser.git.