Add a better prompt when in SSH

[mikeschinkel]

Here is what I'd like to see an improved prompt that make it easier for people to navigate around inside w/o getting lost or confused. Something like this:

WPLib Box {version}[, Git: {remote_url} {branch}] (=> `box help`)
/project/wplib.box/www
$

We can collaborate on what it should actually be but given our box is likely not an environment people will "live" in I think we should give them common info w/o them having to go looking.