Add Slider Control

Signed-off-by: Gordon Smith <gordon.smith@lexisnexis.com>
Abstract Transitions

Signed-off-by: Gordon Smith <gordon.smith@lexisnexis.com>
Add Choropleth Counties

Split States and Counties into two different widgets.
Delete ChoroSurface

Signed-off-by: Gordon Smith <gordon.smith@lexisnexis.com>