show all host entries before the domain

This is basically number of dots in the hostname - 1. Then that is used
for the %Nm in the prompt

git-svn-id: https://svn.sixfeetup.com/svn/private/claytron/dotfiles/trunk@47603 7abc7aa1-7e52-db11-9331-00508bd72530
typo

git-svn-id: https://svn.sixfeetup.com/svn/private/claytron/dotfiles/trunk@47604 7abc7aa1-7e52-db11-9331-00508bd72530
var needs to be global

git-svn-id: https://svn.sixfeetup.com/svn/private/claytron/dotfiles/trunk@47605 7abc7aa1-7e52-db11-9331-00508bd72530