Log Message:
devel/libyang: import libyang-1.0.184

libyang is a YANG data modelling language parser and toolkit written (and
providing API) in C. The library is used e.g. in

* Parsing (and validating) schemas in YANG format.
* Parsing (and validating) schemas in YIN format.
* Parsing, validating and printing instance data in XML format.
* Parsing, validating and printing instance data in JSON format