Updates for simpl_add-ons

Today one new add-on has been completed. It is simpl_research, and adds a new sidebar containing very simplistic links to look for the displayed individual on popular research databases. For this first release it can search Ancestry (UK), Find My Past (Britain), and Family Search. I am happy to discuss (with no promises) adding more or better links on the kiwitrees support forums

Also, simpl_cousins has been updated to include a Dutch translation file. Thanks Chris Geets for that addition.