Moved apps/files/ to mkt/ (bug 1021200)

https://github.com/andymckay/baked

It's super useful when we do big renames like this, because the new "mkt." prefix affects import ordering. By running `baked -i` over the files we change we can have it re-order everything automatically.

(Sadly, yes, baked configuration is manual - and the process needs to be watched over, sometimes baked messes up)