Experimenting with the alternative to PHP based index.

SQL can transliterate values too, and do it the same way
as other comparisons. It's own operators act consistently
across board and handle locale/encoding options
transparently.

This could of course be automated (generation of SQL),
and if we had better DB layer and stuff like prepared
statements, this would become real pretty too.

Ideally, I think there should be "function" that generates
search queries from the given values transparently,
instead of us having to write this type of mess, or using
the application for the searches.

Intentionally left out any type of multi-value support,
or extra parsing since it would increase the results count
when all-fields search functionality is implemented.

Searching sentences containing commas would truly
become impossible unless advanced quote-parser is
implemented.

Also added a small example of searching all fields at
once by feeding HTTP GET search_method parameter
an array. This will invoke notices due to the pages
expecting arrays tho.

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5299 2fea6a4d-a838-0410-917b-93a53c48e9d2