This change will call the writer methods defined on an AR model, if they're
implemented, instead of going behind their back. This also avoids a rails 3
deprecation warning, if the named attributes aren't actually database
attributes.

it is better and faster

Fixes bug in -j and -u options.

Fixes: #194 - add_exclude_condition breaks on tables without ID field - https://github.com/alexreisner/geocoder/issues/194

Also rename :ignore to :geo_only (more descriptive/specific--we might
introduce other options in the future and :ignore is kind of vague).

in request to geocoding service.

Also move some lookup-related methods to Geocoder::Lookup module.

This is in preparation for adding Maxmind as an IP lookup.

Thanks github.com/johanneswuerbach.

Thanks github.com/johanneswuerbach.

This fixes issue #244.

This requires a parameter to be accepted by the block passed to
Geocoder.configure, which means you don't need to remember that the
method is called "config"--you can call it whatever you want.
This behavior seems more standard for configuration blocks.