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

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

Conflicts:
	lib/geocoder/lookups/base.rb

Conflicts:
	lib/geocoder.rb

Removed state from city.

Thanks github.com/johanneswuerbach.

Thanks github.com/johanneswuerbach.

Fixed unit config not working with sqlite distance

Yandex geocoding limitations

Correction in configuration template for :distances

Also move it to a new "Advanced Querying" section.

Add documentation for within_bounding_box strategy

Travis CI integration

Get tests running green under JRuby