Bug 1062 - Disallow implicit serviceref creation.

Remove auto registration of service references by netconf. Old behaviour
was adding ref_ + module name for each interface module implements even
if it is not declared in /services node.

Fix code style warning in config-netconf-connector.

Change-Id: I8dc2b4dffac212d9b8b8243ccd7aaf290b87499b
Signed-off-by: Tomas Olvecky <tolvecky@cisco.com>