Initiating and finishing a manual operation works a bit strange. First
of all the Maximum Manual Operation Time is controlled by a setting
(--id 4) and defaults to 0 (infinite). And instead of waiting for the
timer to expire (which you have to do when its set to 0) you can finish
a manual operation by passing "--no-check".
Note: For some reason no response is given when a manual operation is
written to. That's why execute_action() returns succesfully (with None)
when its executing the "setmanual" action and the response queue size is 0.
A loop around getsetting based on the settings available in the
database to retrieve all settings from the WPU.
Example usage:
> ./itho-wpu.py --action getsettings
> 0. Niet Gebruikt: 0 (min: 0, max: 65535, step: 1)
> 1. Hardware Configuratie: 70 (min: 0, max: 65535, step: 1)
> 2. Jaar Inbedrijfstelling: 2010 (min: 2004, max: 2099, step: 1)
By default direnv outputs this while executing:
```
direnv: loading ~/python-itho-wpu/.envrc
```
In a cronjob this results in emails, or when no MTA is configured:
```
CRON[1095]: (CRON) info (No MTA installed, discarding output)
```
