* Cruft cleanup.
Organized snapcraft.yaml better, and got rid of unecessary bits.
* Cleaned up scripts.
Moved launch.sh into snap-overlay, to be more consistent with
everything else.
Got rid of outdated and confusing configure-the-things script.
* Clarified a comment.
* Got rid of erroneous config file.
* Undeleted config file -- wasn't erroneous!