Rename "contrib" to "tools", tidy up

[reticulatedpines]

contrib was never a great name, it doesn't tell you anything about what it should do. Most things in there vaguely fit under "tools". Rename to that, and split out the contributer named subdirs as appropriate.

Also, delete qemu subdir (after checking for anything that isn't already preserved elsewhere given the qemu-eos repo).

Add 14_to_16.c and any other useful things.