Specify format for configuration backup for VyOS/Vyatta/EdgeOS

[yzguy]

Specify format for configuration backup for VyOS/Vyatta/EdgeOS

[yzguy]

So looking around, seems like variables aren't accessible in the models, as really models.rb is pulling things from the model not running the model file.

Per https://github.com/ytti/oxidized/blob/master/docs/Creating-Models.md, we can either extend the existing vyatta.rb or edgeos.rb and add additional commands, or we can create a new one that is exactly the same as existing file but the cmd line is changed.

We then store it in /home/oxidized/.config/oxidized/models/vyatta.rb, and it will be loaded instead of the one that comes with oxidized.

It would be nice if there were a way with a variable to basically toggle commands that get run detailed in the first comment