Two new functions coap_malloc_type() and coap_free_type() have been
added to centralize the typed memory allocation for Contiki and LWIP.
Currently, calls to memb_alloc(), memp_malloc() and coap_malloc() are
distributed across several modules. The idea of the new functions is
to centralize memory management in one place (mem.c). coap_malloc()
and coap_free() are still available as wrappers for the new functions.