POM: add missing authors and licensing

The BSD license comes from an old email:

	Date: Thu, 31 Mar 2011 09:10:32 +0000
	From: Seitz Arne <arne.seitz@epfl.ch>

	as the plugin is rather simple I think BSD is then the license of
	choice. Thanks for your input.

	Cheers Arne

This email transcript was found at:
https://github.com/fiji/fiji/blob/69aa539f842250103efa3a85e04dae437635f575/LICENSES