ADI data from hive for lightweight themes (bug 1059965)

Fixes [bug 1059965](https://bugzilla.mozilla.org/show_bug.cgi?id=1059965)
Given that the command deletes files at the end, we have to copy files from the `src` folder to a `YYYY-MM-DD` one, that's why it's nested (and there is already a folder in `fixtures/`.