Export method _empty_p for operator TEST_EMPTY for all containers.

m-list.h

@@ -64,6 +64,7 @@
    SWAP(M_C(name, _swap)),						\
    TYPE(M_C(name,_t)),							\
    SUBTYPE(M_C(name, _type_t)),						\
+   TEST_EMPTY(M_C(name,_empty_p)),                                      \
    IT_TYPE(M_C(name, _it_t)),						\
    IT_FIRST(M_C(name,_it)),						\
    IT_END(M_C(name,_it_end)),						\