While at it, also remove unnecessary "#!/usr/bin/env python3" in files
that only get imported, and adjust other empty/comment lines in the
beginnings of the files for consistency.
This makes files easier to read, and makes the pmbootstrap codebase more
consistent with the build.postmarketos.org codebase.
This way we could give the user a rough idea what will be installed,
and also use this to display a short warning about long compile times
(e.g. until the plasma mobile stuff is upstreamed).
Thanks, craftyguy!
- UI is selectable with `pmbootstrap init`. Currently only 'weston' and 'none' are options. It'll automatically pick up any new `postmarketos-ui-*` packages added at later dates.
- splits off weston packages install from postmarketos-base and puts
them into postmarketos-ui-weston. Also note that NO weston packages are
installed by "pmbootstrap install" by default unless the user selects a ui in the `init`
- configuration of weston is now in postmarketos-ui-weston.
- the demos have been spun off to `postmarketos-demos`, and `postmarketos-ui-weston` lists this package as a dependency.