Separate daemon and GUI packages (deb and rpm). Finally, one
can install Autopoweroff's daemon on a server without having
to install the GUI with all its dependencies.

Implemented Resources CPU percentage condition. If the CPU percentage
usage falls below the given threshold for a duration of 1s, the condition is
met. Resolves issue
GH004.

Fixed GH005
'Systems with a KVM switch'. Autopoweroff loaded all the
devices once at startup and the list remained static. Now using
pyinotify, the list is dynamically adjusted as devices are added or
removed.

Minor improvements brought to the GUI such as removing use of deprecated
features, enable icons on certain buttons and realigning widgets.

Fixed GH012:
'Autopoweroff cancelfile filename mismatch'.

Anywhere where is is relevant, the term 'shutdown time range' has been
replaced with 'action time range' including in the configuration file. No
logic has changed.

README.md: Small aesthetic improvement such as adding the Autopoweroff,
AWS and Azure logos and 'Python powered', 'Linux powered' banners with
the accompanying explanation.

All threads are now daemon type. This way, when the main thread dies, all
of its children die too and the whole programs stops.

Removed ARP reverse check since a host that is powered off will remain
registered on the DNS, thus making this test falsely believe that the
host is still available when it is not.

autopoweroffd.in performSleepForNoActionTimeRange() function content is
reformulated to be more concise and duplicate code no longer exists.

Python psutil dependency added to package desc.

Fixed minor logging issue.