Add "static-reference" blueprint extension

Add "static-reference" blueprint extension

Added a blueprint extension, "static-reference", that obtains an OSGi
service and returns the actual instance. This differs from the standard
"reference" element that returns a dynamic proxy whose underlying
service instance can come and go. This is useful especially in cases
where the service exists for the life of the karaf container and you
don't need/want the overhead of the proxy.

Change-Id: I4cbcc7e2b5a85b0a22e50e12f3946d29bfb36c7d
Signed-off-by: Tom Pantelis <tpanteli@brocade.com>