move config out of Python files; don't make hg-ssh-wrapper a dotfile;
update documentation.
# WARNING: when these hooks run they will entirely destroy and rewrite
# ~/.ssh/authorized_keys
[hooks]
changegroup.aaaaa_update = hg update -C default > /dev/null
changegroup.refreshauth = ../../admin/hg-admin-tools/refresh-auth ./hg-ssh-wrapper