[WIP] Restrict autolink to current file

I have a webshop with many products, and some have short sku's. When importing via Magmi, I use automatching of sku's with the same start.
Is it possible to match the sku's only in the current file?
I did some tweaks, to also keep track of the skuList for the 'auto' matchmode, and do a link like this, instead of autoLink.

TODO:
- [ ] Test it
- [ ] Update docs

This hasn't been thouroughly tested, but what do you think of the idea/implementation?