* Improved unknown handling
* Configure option `CLICON_YANG_DIR` is changed from a single directory to a path of directories
* Note CLIXON_DATADIR (=/usr/local/share/clixon) need to be in the list
* RFC8040 Restconf replay support: start-time and stop-time query parameter support
* This only applies to "native" restconf stream support, Nchan mode has different replay functionality
* RFC5277 Netconf replay support using <startTime> and
* Replay support is only in-memory and not persistent. External time-series DB could be added.
* Except clixon-config module due to bug reported below
* Bug: Top-level Yang symbol cannot be called "config" in any imported yang file.
* datastore uses "config" as reserved keyword for storing any XML whoich collides with code for detecting Yang sanit
* Added urn:ietf:params:netconf:capability:yang-library:1.0
* Thanks SCadilhac for helping out, see https://github.com/clicon/clixon/issues/39
* uri_percent_encode() and xml_chardata_encode() changed to use stdarg parameters
* Yang 1.1 feature and if-feature according to RFC 7950 7.20.1 and 7.20.2.
* See https://github.com/clicon/clixon/issues/41
* Features are declared via CLICON_FEATURE in the configuration file.
* logical combination of features not implemented, eg if-feature "not foo or
* Identity without any identityref:s caused SEGV
* Clarified semantics of main yang module:
* -y option to commands MUST specify filename
* CLICON_YANG_MODULE_MAIN MUST specify a module
* yang_parse() changed to take either filename or module name and revision.
* Removed clicon_dbspec_name[_set]().
* Use yang_main_module_name() instead.
* Replaced yang_spec_main with yang_spec_parse_module
* Added yang_spec_parse_file
* The previous XPATH imlementation was very restricted.
* The only function implemented is the Yang extension "current()". No other functions are implemented (eg last(), count()).
* Previous support did no validation of values.
* Validation of types and CLI expansion
* Example extended with inclusion of iana-if-type RFC 7224 interface identities
* CLICON_NACM_MODE config option, default is disabled.
* Added username attribute to all rpc:s from frontend to backend
* Added NACM backend module in example
