perfect square regex: Add regex and unfinished test script
test script for squares: Finish implementation (detect false positives)
test scripts: Parametrize regex filename
multiplication regex: First almost-working implementation of simple method

It only fails with perfect squares, giving them a false negative.
multiplication regex: Fix handling of perfect squares; now works fully
Rename original regexes to make it clear which is which
perfect square regex: comments: fix domain
perfect square regex: Add first winning implementation of simple method

This is 6 characters shorter than the factoring method if zero is not matched.

To match zero, "|^$" must be added to this regex. This results in its only being 4 characters shorter than the factoring method. If there is a shorter way to match zero, I haven't found it yet.
multiplication regex: length-=5
multiplication regex: length-=8
multiplication regex: length-=4
multiplication regex: Possible sacrifice of speed; length-=1

This might result in a very slight drop in speed; I'm not sure.
squares and multiplication regexes: Take advantage of greediness; length-=1 in both
squares and multiplication regexes: length-=12
multiplication regex: Take advantage of greediness some more; length-=2
multiplication regex: Huge speed boost
multiplication regex: Take advantage of greediness some more; length-=2
multiplication regex: Further streamline capturing of larger and smaller factor; length-=6
multiplication regex: Reorganize capturing of larger and smaller factors; length-=5
multiplication regex: Reorganize capturing of larger and smaller factors; length-=1