Feature #1426
Updated by Junxiao Shi almost 10 years ago
`ndn::KeyLocator` class should encode and decode a `KeyLocator` element containing a [KeyDigest](http://named-data.net/doc/NDN-TLV/0.1.1/signature.html#keylocator). support *KeyLocatorValue*=[KeyLocatorDigest](http://named-data.net/doc/ndn-tlv/signature.html#keylocator)