added methods/tests for facet.query params
Working on Date facets

- slider working
- histogram working
Year facets

- Slider with range and boxes for manual input
  - Implemented using jQuery UI
- Histogram with plot of years
  - Implemented using d3.js and vega.js
- New templates
- New tests
Merge branch 'date_facet'

Conflicts:
	adsabs/static/js/facets_components.js
Some config parameters changed