* NOTE: Due to an error in the previous implementation, all XPATH calls on the form `x[a=str]` where `str` is a string (not a number or XML symbol), must be changed to: `x[a='str'] or x[a="str"]`
* This includes all calls to `xpath_vec, xpath_first`, etc.
* All calls to cli_copy_config in CLI spec files must replace 2nd argument from `x[%s=%s]` to `x[%s='%s']`
* The old API is stillenabled. To define the new, define XPATH_USE_NEW in include/clixon_custom.h and recompile
* The previous XPATH imlementation was very restricted.
* The only function implemented is the Yang extension "current()". No other functions are implemented (eg last(), count()).
