Added accessors for reverse iterators.
Added accessors for reverse iterators.


OPENDAP/libdap4,OPENDAP/libdap4,OPENDAP/libdap4,OPENDAP/libdap,OPENDAP/libdap4,OPENDAP/libdap4,OPENDAP/libdap,OPENDAP/libdap4,OPENDAP/libdap,OPENDAP/libdap