use ffmpeg -ss for faster screencap creation
Merge pull request #153 from peterbe/use-ffmpeg--ss-for-faster-screencap-creation

use ffmpeg -ss for faster screencap creation
start screencapture taking at 0
run 2 fetch_screencaptures per run
Run update_event_hit_stats less often because it's slow
Merge pull request #154 from peterbe/run-update_event_hit_stats-less-often-because-its-slow

Run update_event_hit_stats less often because it's slow