location: Add altitude property

Add altitude in meters to geocode-location.

https://bugzilla.gnome.org/show_bug.cgi?id=706130
location: Add CRS property

Add a property defining the coordinate reference system of a
geocode-location.

https://bugzilla.gnome.org/show_bug.cgi?id=706130
location: Add parsing of geo URI

This patch adds parsing of geo URI to geocode-location.

The RFC for the geo URI scheme can be found at:
http://www.rfc-editor.org/rfc/rfc5870.txt

https://bugzilla.gnome.org/show_bug.cgi?id=706130