util/ref: add missing ref implementation
util/ref: add missing ref implementation

This was missing from the previous commit. It provides the Ref-Count
implementation from c-sundry, but now merged into dbus-broker.

Signed-off-by: David Rheinsberg <1e7ff67ac6e6692b085f67edeb10803d9022c525@gmail.com>

bus1/dbus-broker