FrameRetrace demo at FOSDEM

[Mark Janes]

I've made progress on my responsive UI for Apitrace, and gave a short
talk about it at FOSDEM.  If you use Apitrace to debug GL workloads, I
encourage you to watch the talk (demo starts around 10:00):

https://fosdem.org/2018/schedule/event/apitrace/

I hope you'll agree that FrameRetrace is a big step forward for
analyzing traces.  If you have suggestions for more features, please
reach out to me.

I'm currently working on adding GPU Metrics support for non-Intel
hardware, to make a more compelling case for merging FrameRetrace
upstream in Apitrace.

-Mark