attached is a patch which allows slime to track, list and recompile top level forms which have been edited since the last compilation.
I've added a brief description to the manual, here's the executive summary:
When the, customizable, variable slime-record-changed-definitions is non-nil we install before/after edit hooks which keep a list of all the toplevel forms that have been modified and their locations.
The command slime-compile-changed-definitions is run, not bound to any key, we just recompile all the changed forms.
The command slime-list-changed-definitions pops up a simplistic buffer with a list of all the forms which would be cempiled by a call to slime-compile-changed-definitions and the order in which they'd be compiled.
comments welcome. i'll apply this shortly unless it breaks slimes someone's slimewhere slime-record-changed-definitions is NIL (iow i'm using this email to make sure the patch doesn't breax anything, i don't expect it to be 100% bug free or perfect from a UI stand point).