Activate/Deactivate fire at wrong time

Issues:
  Activate/Deactivate events fired at wrong times.
  When scrolling up the active event was firing too soon.

Minor improvements:
  Add method to jump to page.
  Prevent tweening on home/end.
  Pressing F5 should reset to top?

Signed-off-by: Gordon Smith <gordon.smith@lexisnexis.com>