TesseTrails v1.2

I finally got around to making 2 big improvements to TesseTrails:

* I wrote a program to go through all 1500+ tesselations and tag them according to various criteria, such as whether they are Nice, Cool, or Fun, whether they contain dodecahedra, whether it's one of those boring stripey ones, or those random jumbles of hexes and triangles. This tag system ties into the RANDOM tesselation_code feature, allowing us to filter what kinds of tesses we want to see.

* And I did what I should've done from the start, and untangled that finicky mess of trying to fit the background colors and the trail colors into one palette. Now there are two: The trail_palette, and the background_palette. This allows much more flexibility: Previously only MONO fill_mode supported trails of multiple colors, now all fill_modes do!

Cheers!