Xen-AddOn Search Improvements by Xon v2.7.5 v2.7.5

A collection of improvements to XF's Enhanced Search and some for XenForo's default MySQL search.

MySQL & Elastic Search features;
range_query search DSL
allows arbitrary range queries for numerical data
Allow users to select the default search order independent for the forum wide setting.
Re-adds the global option for the default search type
Elastic Search Only features:
Per content type weighting
Adds Elastic Search information to the AdminCP home screen.
Adds a debug option to log the search DSL queries to error log for troubleshooting
Option to extend search syntax to permit;
+ signifies AND operation
| signifies OR operation
- negates a single token
" wraps a number of tokens to signify a phrase for searching
* at the end of a term signifies a prefix query
( and ) signify precedence
~N after a word signifies edit distance (fuzziness)
~N after a phrase signifies slop amount
In order to search for any of these special characters, they will need to be escaped with \.​