Give a preference to left-right reading, i.e <postcode>,<address>
prefers a postcode search while <address>,<postcode> rather does
an address search.
Also exclude non-addressables, countries and state from results when a
postcode is contained in the query.
Search is now split into three functions: for free-text search,
for structured search and for search by category. Note that the
free-text search does not have as many hidden features like
coordinate search. Use the search parameters for that.
