Linked With Role filter

[alasdaircr]

Hello,

I've worked up a patch which allows you to specify the 'role' column when filtering linkMultiples. E.g show me Decision Makers for a bunch of Opportunities. Or just show me all Decision Makers. This worked great up until the recent changes to linkedWith, notLinkedWith etc in SelectManagers/Base.php

I'm now looking into refactoring this in order to continue the support for it in our installation. Do you have any suggestions on how this might be tackled in a more modular way? Supporting multiple linkMultiple columns for instance?

This is how my current patch looks: