slime-sexp-at-point in slime-repl buffers

Calling slime-inspect at a prompt in the slime repl buffer without any other input will suggest the prompt itself ("CL-USER>" or whatever) as the default value to inspect. I can not think of any case where this behaviour would be useful :) The attached patch advises slime-sexp-at-point, when the slime-repl.el contrib is loaded, to ignore the prompt text (if point is in the input area, otherwise the normal behaviour of slime-sexp-at-point applies). Unless anyone objects to the patch (or the implementation) i'll commit this later tomorrow. -- -marco