Since we already have the mini library installed in our setup, we don't
need to make use of external base16 plugins. It provides the same exact
functionality, and seems slim and bug-free. Nothing changes for the
user, but we have 1 plugin less to take care of (and it was
mis-behaving in new versions anyway).
Also set lualine to be reloaded on theme switch so it takes on the
colorscheme as well.
Switching from my custom, brittle, styling implementation `styler` to
the wonder `flavours` program which does exactly the same only with more
clarity, faster and - I would presume - more stable.
