Causes way too much problems with the tinderboxes, thanks to -Werror
getting passed to the liborcus configury, and liborcus apparently is
quite -Werror-unclean.

Thus also revert the initial fixes for those WaEs. (Many more would be
needed, it seems. I rather leave it to Kohei to make upstream liborcus
warning-free.

This reverts commit 083fa89d.
This reverts commit 7e871bba.
This reverts commit 21b5706f.
This reverts commit bed5557e.