ive quote characters with no intervening 
      characters.  Calling routines that require special treatment 
      of null tokens must handle this case. 
 
   3) If the input argument qchar is blank, the returned value of 
      last is first-1, and the returned value of nchar is zero. 

   4) If the input string pointer is null, the error SPICE(NULLPOINTER)
      will be signaled.

   5) If the input string has length zero, last will be set to first-1
      and nchar will be set to zero.  This case is not