lib: Changes made to dependencies of a r-map do not take effect.

lib: Changes made to dependencies of a r-map do not take effect.

Say, more than one sequence of a route-map uses the same named entity
in its match clause. After that entity is removed from any one of the
route-map sequences, any further changes made to that entity doesn't
dynamically take effect.
A reference counter, that allows the named entity to keep a count of
the route-maps dependent on it,  has been introduced to address this issue.

Signed-off-by: NaveenThanikachalam <nthanikachal@vmware.com>