feat(ui-slider, candy-list-* controllers): add support for start/end
date filtering using ui-slider

New feature branch includes:
* new slider in candy-list-{timeline|table}.html views
* refactor and greatly simplify controllers
* candy-list-{timeline|table}.js
* stub several new unit tests for controller logic though not yet
* passing most
* new candies-by-dates filter with unit tests
* unify style of both candy-list-{timeline|table}.html views
Merge pull request #11 from ghachey/ui-slider

feat(ui-slider, candy-list-* controllers): add support for ui-slider