[gtk] Set proc title

Try to set the process title during startup. Before, redshift-gtk appeared as a python process.
This change enables `pgrep redshift-gtk` or `killall redshift-gtk`.
spello: continously => continuously

Signed-off-by: Mattias Andrée <maandree@operamail.com>
Use randr in example of conf file instead of vidmode, randr is superior to vidmode because it supports multple monitors where as vidmode only supports multiple screens

Signed-off-by: Mattias Andrée <maandree@operamail.com>
Merge pull request #48 from maandree/man

Man page improvement and fix typos
Merge pull request #45 from phihag/setproctitle

redshift-gtk: Set proc title using libc prctl
HACKING: Remove PYTHONHOME from example

Should have been PYTHONPATH but since the path is set by the script it is no
longer necessary.
Update fedora spec file for Python3 dependency