Search query builder

[rgrp]

Ability to build up search query using a nice javascript-y interface.

• Add facets by selecting attribute and adding -> search facet options in dropdown -> added to search (with 'x' to remove -- as we currently do).
  • (a bit like the data.hri.fi)
• Some improvements to css
  • See ​http://eutr.ep.io/
• Improvements to faceting
  • Ability to configure faceting and number of items to show (?)
• Pure JS search implementation to make it easy to reuse across site