Merge branch 'cm-add-skip-flag' of git://github.com/cmavromoustakos/geocoder into cmavromoustakos-cm-add-skip-flag

Conflicts:
	lib/geocoder/models/mongo_base.rb
	test/mongoid_test.rb

methods to avoid creating an index by default.

Move to method-level rescue where appropriate

Avoid crashes during calculations. Geocoder.coordinates sometimes
returns nil which causes crashes in the distance and bearing calculations.
By returning a point array of [ NaN, NaN ] this distances will be also NaN
which seems to be a sensible result. If the argument to extract_coordinates
has an unexpected form, also return [ NaN, NaN ].

Change :request_headers to :http_headers (for consistency).

Conflicts:
	lib/geocoder/configuration.rb

Add support for custom HTTP request headers

Geocoder.coordinates sometimes returns nil which causes crashes in the distance
and bearing calculations. By returning a point array of [ NaN, NaN ] this
distances will be also NaN which seems to be a sensible result. If the argument
to extract_coordinates has an unexpected form, also return [ NaN, NaN ].

It's not an ideal name either, but it's short and it's slightly more
specific than "method".

Conflicts:
	lib/geocoder/configuration.rb
	lib/geocoder/stores/active_record.rb
	test/configuration_test.rb
	test/mongoid_test.rb

This addresses issue #195.

Add support for cache stores with :get and :set methods.

Altered the Geocoder#ip_address? method to recognize IP addresses prefixed with ::ffff: as is common with webservers binding to ipv6 sockets

Should have been part of commit eba79f25.

Return zero results more reliably. Formerly an exception was raised when
the table didn't have an 'id' column.