This commit remove urn:AGL:widget:provided-application
in favour of urn:AGL:widget:provided-unit.
In the same time, the feature urn:AGL:widget:provided-api
must be attached to a unit. This will enable to export
more than one API for a unit if needed.
Change-Id: I17ade3651db2cd61402875333d063ee05cf57a10
Signed-off-by: José Bollo <jose.bollo@iot.bzh>