always return emtpy values when using the range slider + cleanup
small range formatting fix
added ability to format search result dates
dont include highlighting parameters if no fields are set to be highlighted
fixed the way default sort field is implemented
made range facet settings dependent on the field being a -date- Solr field. This needs to be updated when we want to use integers for ranges
split out Solr URL from Solr configuration form
Merge pull request #121 from DannyJoris/7.x

7.x various updates
Merge branch '7.x' of https://github.com/Islandora/islandora_solr_search