opengl: Clear up a few header issues, no functional change [2 commits]

• Philippe voiced that he was the original author in the ML, adding Philippe to the headers to ensure credit is given.
• Adding Precision Insight copyright back *just incase* It's unclear if Precision Insight code was used given Philippe's comments in the ML, lets be safe and add it back. As we have Brian's permission for these changes I feel comfortable with it.