Search changes

[ghost]

In order to improve search results, as described in #63 in openrural/columbus-county-nc, I've made a number of small changes to the OpenBlock search code.

In ebpub.ebpub.db.views.search:

• For ambiguous addresses, show results similar to ambiguous Blocks. Both addresses and Blocks make use of the block disambiguation page. This is because the lowest-level at which one can search is a Block (rather than a specific address).
• Better sorting on ambiguous Blocks. We split up the results according to which city they are in, and order them by street number and direction (N, S, E, W). It's a great improvement on usability in a multi-city installation.
• Commented out Place search things. OpenBlock's place search is error-prone. Currently, we aren't using Places but this code should be revisited if we ever do.
• Fixed 500 error bug when URL of address can't be reversed. If the URL of an address cannot be reversed, then a 500 error was thrown. It seems preferable to simply not return a result.

in ebpub.ebpub.geocoder.base.AddressGeocoder._db_lookup:

• Don't suppress results if no street number is given. Results were suppressed if a street number wasn't given with the location query. This makes a big difference in searching but I'm not sure what effect it has elsewhere.
• When searching for results in a city, also search in cities with a matching normalized name. That way, when someone searches for something in Whiteville that we've got listed in Whiteville Area, we can still find the results.

In ebpub.ebpub.geocoder.base.full_geocode:

• Allow more than one Location result to be returned. So that we can return both Whiteville and Whiteville area when someone searches 'whiteville'.
• Commented out Place search things.