Previously, entities always appeared in the middle of the screen
with an unlocked y-axis. Now, they will appear on the ground
if snapping is enabled and the ground is in sight.

This means you should be able to type the singular
or the plural form for most units now.

This also adds an option to enable editing *any* attribute

Custom attributes will take string input and then decide if it is an acceptable
type of unit.

Also add a 'setup' script that both creates a directory and runs
the bounds-fixer script on it