willdurand/Geocoder — pull request #85 by Baachi (2012-09-10 19:59:22+00:00)
Title: Add chainprovider

As we discuss in issue #80, i have added the `ChainProvider`.

The chainprovider wraps one or more provider.
He tries each provider that he contains. If a provider throw an exception,
the chainprovider will skip the provider and continue with next provider.