Support using the same numeric-valued metatag twice in the same search.
Numeric-valued metatags are those taking an integer, float, filesize, or
date argument. Previously using the same metatag twice would cause the
second metatag to overwrite the first metatag.
Examples:
* "id:>5 id:<10"
* "width:>500 width:<1000"
* "date:>2019-01-01 date:<2020-01-01"
Support using quoted values with all metatags. For example: user:"blah blah",
pool:"blah blah", commentary:"blah blah", etc. Things like rating:"safe",
id:"42" also work. Both single and double quotes are supported.
Also make the status: and rating: metatags fully free. Before only
status:deleted and rating:s were free.
