+/** \brief returns one token (if any)
+ \param chain ICU chain
+ \param status may include ICU error on failure
+ \retval 0 error or end-of-tokens (no more tokens)
+ \retval >0 token number (1, 3, 3, ..)
+
+ This function tries to move to "next" token in assigned
+ C-string .. Or returns 0 if no more is to be found
+*/