areEqual =
AreStructsEqualOnFields(struct1,struct2,theFields)
Returns 1 if two structs share the same value on each of the passed
fields, 0 otherwise. Only checks numeric and string fields.
For fields that are cell or struct, it does check that they are
of same type, but doesn't descend and check the values.
5/1/05 dhb, jmk Handle cell and struct fields, a little bit.
Psychtoolbox/PsychOneliners/AreStructsEqualOnFields.m