Implemented recentRiderArea and recentRiderSummay using S-Store window.

Implemented anomalies (travel exceed speed limit) detection in pull request #15.
Implemented recentRiderArea that includes the rectangular coordinate and the square mile area of recent riders has been to.  This information can be use to dynamically re-size the map to best capture all users on one screen.
Implemented recentRiderSummary that include distinct rider count, [max, min, avg] speed of recent riders.