Add support to accept-language and email parameters in OSM Geocoder.

accept-language=<browser language string>
   Preferred language order for showing search results, overrides the value specified in the "Accept-Language" HTTP header.
   Either uses standard rfc2616 accept-language string or a simple comma separated list of language codes.

email=<valid email address>
   If you are making large numbers of request please include a valid email address
   or alternatively include your email address as part of the User-Agent string.
   This information will be kept confidential and only used to contact you in the
   event of a problem, see Usage Policy for more details.

http://wiki.openstreetmap.org/wiki/Nominatim