Adding a download script

Moving this over from a seperate folder. I realized there's no reason to
have these two util tools in different repos. This is a very basic shell
script and should eventually get moved over into Python like the
other...or eventually become part of the nodejs system in the main
visualization application.
Better data directory cleanup.

I don't want the script to remove the README every time.
Simpler names for the scripts

Since this whole fodler is for scripts, maybe I don't need any verbs,
just what we're getting. Shorter to type.