Clean chroot builder

The following additional variables are supported:

• DESTDIR -- determines environment for staged installs,
• PREFIX -- determines the value of BINDIR (default: $${HOME}/.local).
• BINDIR -- determines where the script will be installed (default: $(PREFIX)/bin).

To install, just run make or copy the script ccb wherever you want.
To uninstall, just run make uninstall, providing the same make variables given during installation.

To change the value of any make variables, run, e.g., make FOO=bar install

The script requires the following to run:

• artix linux
• zsh
• pacman
• mkchroot from package artools-base
• mkchrootpkg from package artools-pkg

In a directory with an up-to-date PKGBUILD, run

`ccb [options]`

options:

-h              show this message
-f              run with force (overwrite any existing chroot)
--chroot CHROOT choose a different chroot than the default ($HOME/chroot)
--no-install    don't install the package