Get the macro-step slime facility working with Clasp

[drmeister]

Slime has a nice facility (macro-step) for expanding macros interactively. Each backend must implement a couple of functions to make it work. https://github.com/slime/slime/blob/master/swank/backend.lisp#L717
All of the functionality is available in Clasp to make it work except for MACROEXPAND-ALL - which can be obtained from the agnostic-lizard Common Lisp system available in quicklisp.

I've been in contact with the author of agnostic-lizard and he's happy to provide a clasp specific version of MACROEXPAND-ALL that we can incorporate into Clasp to get macro-step to work. It just all needs to be tied together.

It's probably a couple of hours work and I'm happy to point whoever wants to do it in the right direction.

[phoe]

Context: a Clasp MACROEXPAND-ALL implementation is missing in Swank and trivial-macroexpand-all.

[robocode51]

I know very little about CL/Slime internals but I could try. Please point direction if feasible.

[Bike]

@boscodsouza82 Would basically have to be an adaptation in Cleavir (https://github.com/s-expressionists/Cleavir/) to merely macroexpand instead of generating an AST.