Log Message:
graphics/wallust: update to 2.5.0

 - pywal template compatibility: #5
    - output colors in RGB,RGBA,XRGB and singular color channels #5 1/2
    - add {wallpaper} variable to templating fix #5 2/2
    - add {cursor} variable
    - add {alpha} variable
 - new flags:
      -b/--backend to use a backend other than the config file
      -c/--colorspace to use a custom colorspace, other than the one in the
       config file
      -C/--config-path to use a custom config file #12
      -f/--filter to use a filter other than the one in the config file
      -o/--overwrite_cache to ignore cached palette
      -n/--no-cache don't cache result palette
 - new filters:
    - harddark - "hard hue" colors
    - softlight - more "pastel" like colors
 - built-in pywal themes (can be turn off with a compile-time feature)
 - can read pywal colorschemes and terminal-sexy formats (both json) #8
 - don't quit on errors while templating
 - nix pkg to the readme #10
 - fix building on windows #14
 - multiple fixes, improvements, refactors
 - update dependencies