When given a coordinate off the coast of a large town, the entire
town may end up in the potential results during the reverse query.
Postgres then needs to sort tens of thousands of results before it
can determine the clostest one. Given that the results at such a
large search radius are bound to be imprecise anyway, restrict
the number of results postgres should consider to 1000.
Make sure to use the classtype tables with near search and
allow to search for arbitrary key/values (forbidding it
for viewbox searches).
Add tests for near queries.
Reenable search by the secret special term [key=value]
matching against the given main tag. Note that for most
cases that works only for tags that also have a special
search table.
When searching for POIs in place_classtype_ tables limit the number
of objects considered to 300. The distinct and order by clauses
forced until now to retrive all matching objects and order them
first which can cause long running queries when retriving them
for large areas like the US.
Fixes#735.
