* Renamed yang file `ietf-netconf-notification@2008-07-01.yang` to `clixon-rfc5277`.
* Cligen uses posix regex while yang uses XSD. It differs in some aspects. A translator function has been added for `\d` -> `[0-9]` translation, there may be more.
* [ietf-netconf-notification@2008-07-01.yang validation problem #62](https://github.com/clicon/clixon/issues/62)
* 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
* Names lexically correct (NCName)
* Syntactically Correct handling of '<?' (processing instructions) and '<?xml' (XML declaration)
* XML prolog syntax for 'well-formed' XML
* <!DOCTYPE (ie DTD) is not supported.
This affects installations where the libraries are installed outside
the normal library search paths (e.g. FreeBSD puts ports libraries
in /usr/local/lib by default, which is not on the default lib path)
