This commit adds the Data Science Toolkit as a lookup type.  The DSTK behaves identically to the Google Maps API with the exception that it can be run behind your own firewall.  More information about this tool can be found here: http://www.datasciencetoolkit.org/

instead of inferring from response length. This is less than ideal but
it fixes issue #396 and, given what appears to be MaxMind's inconsistent
response lengths, it may not be possible to do much better.

Ideally, datenimperator-add-ovi would have been rebased to master before
being merged.

Use \A and \z in regular expressions to avoid newline issues. Also, do not consider any address that begins with 127 to be a loopback IP.

Should close #374.

Should resolve half of #374.

Now it is necessary to specify which service is being used:
  Geocoder.configure(:maxmind => {:service => ...})
where '...' is one of: < :country | :city | :city_isp_org | :omni >

If you do this:

  Geocoder::Query.new("Kremlin, Moscow", :params => {:language => "ru"})

you should get a response in Russian ("ru") regardless of the value set
in Geocoder.configure(...).

Now every fake query does not need to be listed in the code, a fixture
just needs to be added.

Changed since pull request was submitted.

Also add test for method presence in all lookups.

Make Geocoder.configure accept a hash (now preferred) and add
Geocoder.config method (for reading config). Deprecate old syntax.