Simple product relater

[liam-wiltshire]

This was a feature request on SF: https://sourceforge.net/p/magmi/feature-requests/25/

Not fully feature-complete yet, but works as an initial way to link a simple product to an existing configurable product (need to add bundled and grouped products).

Intended Usage:

Uses a new column called "parent_product", which is a comma-separated list of link types and SKUs - e.g.

parent_product
configurable:T-SHIRT,grouped:T-BUNDLE

Would link this simple product to the configurable T-SHIRT, and the grouped T-BUNDLE

Notes

This is created as a new plugin so it doesn't have any impact on current integrations.
Will continue to submit PRs as other parts of the feature set are done.