Introducing geiser-overlay

[port19]

Hi all,

I have written a small emacs package for scheme evaluation result overlays.
The project readme includes a demo image for those unfamiliar with the concept.
Check it out: https://github.com/port19x/geiser-overlay

Schemers familiar with Clojure will be familiar with this style of evaluation 
results rendering from cider.
After cider invented it, eros brought it to Emacs Lisp.
Then sly-overlay brought it to Common Lisp.
Today I'm following in the footsteps of these three packages by bringing it to 
Scheme.

Technically speaking, geiser-overlay shares a lot of code with sly-overlay.
In fact, development started out with a s/sly-/geiser-/g of sly-overlay.
Thanks to jao for helping me fix a bug caused by a misunderstanding of geiser 
evaluation internals.
Melpa inclusion is well under way.

I hope you like it as much as I do.

Best,
port19