.bash_profile: Support hostname aliases defined in ~/.ssh/config

`~/.ssh/config` allows for the usage of hostname aliases, formatted as follows:

    Host first_alias second_alias third_alias
    HostName foo.example.com

This change makes sure these aliases are parsed out individually and added to the autocomplete list.

Ref. mathiasbynens#178.

.bash_profile

@@ -23,7 +23,7 @@ for option in autocd globstar; do
 done
 
 # Add tab completion for SSH hostnames based on ~/.ssh/config, ignoring wildcards
-[ -e "$HOME/.ssh/config" ] && complete -o "default" -o "nospace" -W "$(grep "^Host" ~/.ssh/config | grep -v "[?*]" | cut -d " " -f2)" scp sftp ssh
+[ -e "$HOME/.ssh/config" ] && complete -o "default" -o "nospace" -W "$(grep "^Host" ~/.ssh/config | grep -v "[?*]" | cut -d " " -f2 | tr ' ' '\n')" scp sftp ssh
 
 # Add tab completion for `defaults read|write NSGlobalDomain`
 # You could just use `-g` instead, but I like being explicit