slider moving and adjust speed

[kwangil-jason-yoo]

• Fixed) keep playing when changing the theme -> reset when changing the theme
• Fixed) after a pause, the animation restarted -> starting from the paused location
• Reset Button Added
• Speed Adjust Button Added
  1. x0.5 slower the animation by clicking the button. (can be repeated)
  2. x2.0 faster the animation by clicking the button. (can be repeated)

[geobarry]

Please address the following three issues:

1. If current date is not the last date, play button should start from current date. Right now it always goes back to Feb. 26.
2. The four buttons distract too much from the main map. They should be aligned in a single row or col, and all be the same color. Even better, we should develop a common stylistic theme for these buttons and the drop-down options for data source, map theme and map type.
3. The animation is very choppy, I'm not sure why. The transitions should be smooth because of the D3 transition call in updateMap(). Maybe we need to create a simple page with just one circle to experiment and figure out how to get this right.