jre.sh cannot be sourced since append_path is unset in /etc/profile at the end.
So we instruct to source /etc/profile instead.

Fixes #6

fixes FS#66339

Purge all packages that have been removed from the repositories but are
still under version control, cf. [1] for details.

[1] https://mailman.archlinux.org/pipermail/arch-dev-public/2014-August/026519.html