Search Improvements 2.16.1

• Fix content weighting values being clamped to 0 or 1
• Fix "Allow empty search" to work as expected without ElasticSearch Essentials installed

• Only apply content weighing if more than 1 content type is permitted to be returned in a search query

• Add default search order option
  • XFES for XF1 used to have this option, but it was removed in XF2.
  • Support setting "Word Count" as the default search order, if Word Count Search is installed.

• Add "allow empty search" option.
  • Allows MySQL search to support * searches like XFES does.

• Add an icon
• Respect per-user default search order when viewing the advanced search page.

• Fix XF2.1 adding options to account preferences page