pywal (also known as wal) lets us change color schemes with a cache
directory instead of editing config files directly. This helps us
separate the dotfiles from the color schemes.
This commit removes explicit color settings from my dotfiles, which are
now managed by pywal. Dunst has been added to show any notifications
that I may want to use in the future. The colors.Xresources file is used
to prevent urxvt from using a depth of 32.
My custom colors.vim file has been removed in favor of wal.vim, which
solves some problems I had to manually resolve myself and should make
things easier to maintain in the long term.
Note that pywal also supports base16 color schemes, as well as any other
color scheme you can think of.
