Tracking/Polling CurrentTime Manually
-------------------------------------
- Necessary for most flash players and browsers that don't trigger timeupdate events. 
- In VJS 1-2, we always tracked time because timeupdate was rare.
- Now most browsers support it well. There is a delay bug in the current Chrome.
    http://code.google.com/p/chromium/issues/detail?id=92251
  Andrew from Chrome told me it would be fix in an upcoming release.
Going to rely on browsers timeupdates when available now.