[Fontconfig] 'loading' vs. 'scanning' config files

[Werner LEMBERG]

If I say

```
FC_DEBUG=1024 fc-list
```

I get

```
Loading config file from /etc/fonts/fonts.conf
Scanning config dir /etc/fonts/conf.d
Loading config file from /etc/fonts/conf.d/10-group-tt-hinted-fonts.conf
Loading config file from /etc/fonts/conf.d/10-group-tt-hinted-fonts.conf done
...
Loading config file from /etc/fonts/conf.d/90-synthetic.conf done
Loading config file from /etc/fonts/fonts.conf done
Scanning config dir /usr/share/fontconfig/conf.avail
Scanning config file from /usr/share/fontconfig/conf.avail/10-autohint.conf
Scanning config file from /usr/share/fontconfig/conf.avail/10-autohint.conf done
...
```

What is the difference between 'loading' and 'scanning'?  And why does
FontConfig look at all into the `conf.avail` directory, which is
nowhere specified in a configuration file?


    Werner