Add support for a relativeLocation output parameter

Add support for a relativeLocation output parameter that contains a relative location description of the locality that can be used to disambiguate duplicate names. For example, there are two populated places called Mill Bay in BC. According to BC Geographical Names (http://apps.gov.bc.ca/pub/bcgnws/), their relative locations are as follows:

Mill Bay (N side of Nass Bay, Range 5)

Mill Bay (W side of Saanich Inlet between Bamberton and Cobble Hill)

An application can append the relativeLocation to the fullAddress for display in the autocompletion list of address choices. Relative location descriptions are available from BC Geographical Names.