mathiasbynens/dotfiles — pull request #178 by nateober (2013-01-23 21:52:37+00:00)
Title: Adding tr to ssh autocomplete allows aliases. 

ssh config allows for the usage of aliases that are addressed like so:
Host first_alias second_alias third_alias
HostName my.hostname.com

Adding the tr in the complete command parses these aliases out and adds them to the autocomplete list.