Search Improvements 2.17.4

• Fix the "Default search order" option would get reset when changing "Search options" under Enhanced Search Setup page

• Fix weight by content type for XF2.2

• Re-add "On error, log search DSL" option, default on.

• Improve extendibility of weight-by-content-type feature (Allow custom searches to opt-in to content weighting for single type searches)
• Improve compatibility with ElasticSearch v7+
• Support float-point weight values in weight by content-type
• Ensure XFES doesn't swallow the actual error message for a query failing instead of "all shards failed" message (backport for older versions of XFES)

• Improve extendibility of weight-by-content feature

• Allow weight-by-content to be extended.
• Compatibility update when resolving an extended class to the root class
• Require Standard Library by Xon v1.2.0+

• Compatibility fix for Threadmarks v2.8.0+ and possibly other add-ons which may extend search page defaults
• Requires php 7.0+
• Now depends on Standard Library by Xon
• Support XF2.2+

• Improve MySQL range-search support for Report Improvements warning points search

• Require XF2.1+
• Rework "Allow empty search" support, support for XF2.1.8+ features and also XF2.1.0+

• Add missing phrase for admincp user change log