scripts/generate-plugins.sh uses GTRI (c) instead of a generic template

[tm132]

The generate-plugin.sh generates plugins with GTRI copyright notices in the comments which can be confusing to people outside of GTRI using the script. Since SCRIMMAGE is an open-source project usable by anyone, things like this should be written to be more generic in nature since it won't be just GTRI people using this. I had a customer that was using it to create some models in, and they were confused when it generated the GTRI copyrights and weren't sure if they were doing something wrong.

The templates should have blocks like $YOUR_COMPANY_HERE, and $YOUR_LICENSE_HERE with an example after it to indicate that you should fill these things in to suit your company's and project's needs within the constraints of SCRIMMAGE's overall license.