Yangtools cannot release because - fixing

- yangtools cannot release because the projetc.version dependency in
dependency management keep changing with the project that includes it,
so fixing it
- restconf dependency and other version should not be duplicated in
multiple poms
- the version property in the common/parent/pom.xml file need to be
the authoritative versions else the features file cannot relay on it

Signed-off-by: Giovanni Meo <gmeo@cisco.com>