Remove docs subpackage

There's no point in having this subpackage since it's empty.
Remove Python dependencies from analyze

systemd-analyze is rewritten in C from a long time now.
Install systemd into the default path

Mer installs systemd on /lib, instead we want the default which is
/usr/lib. Some day we will implement UsrMove completely so this feels
just right.

Besides, why lose time fighting defaults that are right for us?
Revert "Install systemd into the default path"

This reverts commit d5f840a78ca978d739a46b0a0aee754fabef5346.

Requires full UsrMove to work.