Range slider

[antony-wilson]

This branch adds two new widgets with make use of jQRangeSlider:

• a numeric range slider
• a date range slider

Currently they are specialisations of LiteralInput data_type='string'

If a string input has an id starting with range_slider then a numeric range slider is created. If the input has defaults in the format of 'nnnn|nnnn' then they are used to set the range of the slider

If a string input has an id starting with date_slider then a date range slider is created. If the input has defaults in the format of 'yyyy/mm/dd|yyyy/mm/dd' then they are used to set the range of the slider

[antony-wilson]

Updated

range_slider:

• identified by any input ID that ends in "NumericRange"
• provided as:<start>/<end>

date_slider:

• identified by any input ID that ends in "DateRange"
• provided as: <YYYY-MM-DD>/<YYYY-MM-DD>