This takes handling of chassis power and sleep keys as well as the lid
switch over from acpid.
This logic is enabled by default for power and sleep keys, but not for
the lid switch.
If a graphical session is in the foreground no action is taken under the
assumption that the graphical session does this.
We finally got the OK from all contributors with non-trivial commits to
relicense systemd from GPL2+ to LGPL2.1+.
Some udev bits continue to be GPL2+ for now, but we are looking into
relicensing them too, to allow free copy/paste of all code within
systemd.
The bits that used to be MIT continue to be MIT.
The big benefit of the relicensing is that closed source code may now
link against libsystemd-login.so and friends.
