wallust - Generate colors from an image

Features
 - Config file at ~/.config/wallust/wallust.toml
     - templating integrated in a config file
     - backends, colorspaces and filters
     - configurable threshold
 - cache scheme palette at ~/.cache/wallust

Templating & Config File
 - You can use wallust generated colors in your program by __template__ing
   them in it's config file and add a new entry to wallust.toml