Specify output file paths in config file

Initial support for specifying output file paths in a config file using
configparser.

Reads from config file specified on commandline or defaults to
/etc/archmap.conf

Includes stub config file
Refine 'sys' and 'configparser' imports
Comment ConfigParser code
Add systemd service and timer

This commit adds a systemd service that runs ArchMap and a timer that
activates the service each day.
Merge pull request #5 from kyrias/systemd-units

Add systemd service and timer
Moved 'sys' and 'configparser' imports
Change output filenames to match docs (temporary?)
Re-run archmap.py
Update 'Use' with info about the config file