Signed-off-by: James McCarthy <james2mccarthy@gmail.com>

Was causing problems when installing with bundler from Git URL.

Specify path to VERSION file relative to lib/geocoder.rb.

Figures out whether query is an IP address so you don't have to.

Was ignoring non-ASCII characters. Thanks to github.com/supergivi for
reporting the bug.

...for Result instance methods mistakenly called on an array.

After further consideration, multiple results should be the default
behavior for this method. Some services only return one result (eg: any
IP-based service) but a great feature of advanced services like Yahoo
and Google is that they return an array of choices when doing a vague
search like "100 Main St" with no city, region, or country specified.

This allows us to add a method for expiring cache keys and generally
gives us more control over the cache interface.

More than one result is very rare and it's not clear how one would
evaluate the choices. If this is required in the future a new method
can be added.

Add Geocoder::Orm::Base module.

Also move 'address' and 'coordinates' methods from Geocoder::Lookup::Base
to Geocoder. This simplifies the interface and allows us to choose a
lookup engine dynamically for other types of geocoding (eg: IP addresses).

Prepare to add support for Yahoo in addition to Google.

Add implementation for Google and anticipate addition of Yahoo (supply
config option).