zeroconf: use port from server instead of picking port from config (issue3746)
In order to get the port, wrap create server instead of
hgweb_mod/hgwebdir_mod.
to build a new macosx binary package:
install macpython from http://www.python.org/download/mac
install py2app from http://pythonmac.org/packages/
make sure /usr/local/bin is in your path
run bdist_mpkg in top-level hg directory
find packaged stuff in dist directory