Force specfify ip_lookup on search, even when ip_address? fails

Fix bug in yandex results

This is not currently returned by any of the supported lookups,
but it COULD be.

Handle Bing over limit when header 'X-MS-BM-WS-INFO' is set to 1

Handle freegoip's updated response format

Store service arrays in instance variable

It makes it easier to add a custom lookup class or filter available
services by manipulating the correct service array.

Add license to gemspec

Added some more POI type options for nominatim's results

This reverts commit 196777ea.

Explicitly Load Railtie in Test Env

Fix Yandex city error when JSON does not include 'AdministrativeArea'

This reverts commit 082c526d, reversing
changes made to 242a29f8.

Some regions appear to not return this in JSON

Test suite failed because railtie wasn't loaded (because
Rails/ActiveRecord are stubbed out in test env). This initializes
it explicitly in test_helper before any models get defined

Update README.md