* `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
* CLICON_YANG_MAIN_FILE Provides a filename with a single module filename.
* CLICON_YANG_MAIN_DIR Provides a directory where all yang modules should be loaded.
* Change all @datamodel:tree to @datamodel in all CLI specification files
* If you generate CLI code from the model (CLIXON_CLI_GENMODEL).
* For backward compatibility, define CLICON_CLI_MODEL_TREENAME_PATCH in clixon_custom.h
* Removed return value ymodp from yang parse functions (eg yang_parse()).
* New config option: CLICON_CLI_MODEL_TREENAME defining name of generated syntax tree if CLIXON_CLI_GENMODEL is set.
* 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.
