Data partition contains useless config files

[lurch]

I just tried using the "network install" feature of NOOBS 1.3 beta, and decided to try the "Advanced Data Partition" option. It all works fine but when I mount this data partition I can see it contains config.txt and os_config.json files which serve no purpose whatsoever, as this partition isn't storing an OS.

I guess this is another situation where the Data Partition should just be special-cased, similar to the way it doesn't get displayed in the boot-selection menu.

[lurch]

...and similarly, the "Edit config" button should be disabled for the Data Partition - currently if you try to edit the Data Partition's config, it displays an error dialog saying "Error mounting boot partition" and then displays an all-grey config editor.