* 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
* 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