Beaver Lake Preserve: Add bench and correct trail access rights

Harvey Manning Trailhead. Remove duplicate restroom point. Add second information sign. Correct position and direction of view point.

Harvey Manning Trailhead. Correct routing of Shangri La trail. Set it so the two segments now meet at the road.

Revise Harvey Maning trailhead info. Add porta-potty, correct position of info sign, remove reference to office which was torn down a few years ago.

Remove reference to 7-11 store and gas pumps that closed last year.