Tooltips for SLIME

I came across tooltip-help.el while browsing EmacsWiki for useful SLIME scripts. I tried it out with elisp and it's really great, so I wanted to do something similar for SLIME.

First, you need a trivial change to tooltip-help.el so that the result can come from any buffer, not just *Help*. The problem, then, is that SLIME's slime-describe-symbol is an asynchronous operation, so the *SLIME Description* buffer is not yet ready when th-elisp-get-help-text tries to read the description from it. So here's a synchronous version:

(