RequiredFields:

--------------------------------------------------------------------------
   Returns 1 if the data structure g has the required fields in r
--------------------------------------------------------------------------
   Form:
   x = RequiredFields( g, r )
--------------------------------------------------------------------------

   ------
   Inputs
   ------
   g            (:    Data structure
   r            {}    Cell array with required fields

   -------
   Outputs
   -------
   x            (:)   Returns a 1 if g(k) does not have all required fields

--------------------------------------------------------------------------