Resystem common service package

This Python3-only package provides different classes and functions which are used in various services, either proprietary or open, such as res-scheduler.

It supposes asyncio environment.

• argument_parser.py provides scattered argparse support.
• child_process_protocol.py allows single parent - multiple children process operation, similar to classic web servers like Apache or (g)unicorn.
• configuration.py includes Config class and different helpers for building a nice JSON-based configuration system.
• logger.py supplies Logger class which simplifies and colorizes logging (other classes are supposed to inherit from it - screw the incapsulation).
• systemd_watchdog.py - systemd watchdog wrapper (used in modern Debian/Ubuntu versions).
• utils.py - various random functions.

Released under New BSD license.