this is the correct way to write a build system. one toplevel Makefile.am with the rest of the directories having include Makefile.mk files.
additional authors:
Iván Briano <ivan.briano@intel.com>
If one have systemd but installs to ~/ (no root) then installing
e18.service hurts.
Have e18.service to be generated using @prefix@ so it won't hardcode
to /usr/bin, removing "-locked" as that can be configured in the GUI
and in some cases you just want your e18 without lock/password.