*sh: remove ssh-reagent

I'm satisfied now that I won't need this again; keeping `timeout3`
around though as it may still prove useful.

Signed-off-by: Wincent Colaiuta <win@wincent.com>
*sh: reassign `r` alias to `git refresh`

Now that the old use of `r` is no more, we're free to use it for `git
refresh`, which is a more natural fit anyway.

Signed-off-by: Wincent Colaiuta <win@wincent.com>