Add "specific-reference-list" blueprint extension

Added a blueprint extension, "specific-reference-list", that obtains a specific
list of service instances from the OSGi registry for a given interface. The
specific list is learned by first extracting the list of expected service types
by inspecting RESOLVED bundles for a resource file under META-INF/services with
the same name as the given interface. The type(s) listed in the resource file
must match the "type" property of the advertised service(s). In this manner, an
app bundle announces the service type(s) that it will advertise so that the
extension knows which services to expect up front. Once all the expected services
are obtained, the container is notified that all dependencies are satisfied.

This new extension will initially be used by the bgpcep project.

Change-Id: I3bc6a72134b33c744fbb48fd645dd3a0ca54673d
Signed-off-by: Tom Pantelis <tpanteli@brocade.com>