Fix clock.tick throwing away scheduled functions in case where clock missed the schedule by _exactly_ the interval (pathalogical, but this computer seems very good at it!).
Fix clock.tick throwing away scheduled functions in case where clock missed
the schedule by _exactly_ the interval (pathalogical, but this computer seems
very good at it!).

mpasternak/pyglet-fix-issue-518-522,cledio66/pyglet,gdkar/pyglet,mpasternak/pyglet-fix-issue-518-522,Austin503/pyglet,mpasternak/pyglet-fix-issue-518-522,shaileshgoogler/pyglet,Alwnikrotikz/pyglet,mpasternak/michaldtz-fixes-518-522,Alwnikrotikz/pyglet,cledio66/pyglet,odyaka341/pyglet,mpasternak/michaldtz-fix-552,cledio66/pyglet,shaileshgoogler/pyglet,odyaka341/pyglet,google-code-export/pyglet,arifgursel/pyglet,shaileshgoogler/pyglet,shaileshgoogler/pyglet,mpasternak/pyglet-fix-issue-552,Alwnikrotikz/pyglet,arifgursel/pyglet,mpasternak/michaldtz-fix-552,xshotD/pyglet,xshotD/pyglet,mpasternak/michaldtz-fix-552,mpasternak/pyglet-fix-issue-552,gdkar/pyglet,Austin503/pyglet,mpasternak/pyglet-fix-issue-552,Austin503/pyglet,kmonsoor/pyglet,Alwnikrotikz/pyglet,Austin503/pyglet,mpasternak/pyglet-fix-issue-518-522,mpasternak/michaldtz-fixes-518-522,mpasternak/michaldtz-fixes-518-522,gdkar/pyglet,shaileshgoogler/pyglet,google-code-export/pyglet,qbektrix/pyglet,qbektrix/pyglet,kmonsoor/pyglet,gdkar/pyglet,odyaka341/pyglet,qbektrix/pyglet,cledio66/pyglet,kmonsoor/pyglet,mpasternak/pyglet-fix-issue-552,cledio66/pyglet,qbektrix/pyglet,arifgursel/pyglet,xshotD/pyglet,gdkar/pyglet,mpasternak/michaldtz-fix-552,google-code-export/pyglet,xshotD/pyglet,arifgursel/pyglet,google-code-export/pyglet,kmonsoor/pyglet,Austin503/pyglet,xshotD/pyglet,kmonsoor/pyglet,Alwnikrotikz/pyglet,mpasternak/michaldtz-fixes-518-522,google-code-export/pyglet,odyaka341/pyglet,odyaka341/pyglet,arifgursel/pyglet,qbektrix/pyglet