Add hi-amplitude version of each image.

This is still pending implementation of the triangle version of things.
Initial triangle-based Perlin noise.

The triangles used are not equilateral yet.
Use equilateral triangles.
Re-render with a new seed on right arrow keypress.

This makes it easier to understand how common certain
non-natural artifacts are. In particular, I'm looking for
lines or sort-of-line-ish patterns that seem to appear
along axes lines for the two grids I have so far.

Idea 1 has axis lines north-south and east-west.
Idea 2 has axis lines along a hexagonal grid determined
by the equilateral triangles I'm using.
Add fancy (trans/rotated pieces) tri Perlin noise.

My guess that it has less linear artifacts seems to be
correct, based purely on what it looks like to me.
I'm happy with the results.
Add a non-working need_to_draw boolean.

This boolean currently only suppresses drawing at startup.
My goal was to reduce CPU-clogging when no new images were
rendering. However, I couldn't get it to work, and I suspect
that each time love.draw() is called, it automatically
clears the drawing surface for you, so that an empty call will
actually do something, so that it's not the do-nothing operation
I was hoping for.