* Made NETCONF message handling more strict according to RFC 6241
* Set `CLICON_NETCONF_MESSAGE_ID_OPTIONAL` to true to accept omission of message-id attribute
* Fixed: [need make sure message-id exist in rpc validate #240](https://github.com/clicon/clixon/issues/240)
* Removed xml-stats non-config data (replaced by rpc `stats` in clixon-lib.yang)
* Added option `CLICON_YANG_UNKNOWN_ANYDATA` to treat unknown XML (wrt YANG) as anydata.