In this patch, we've added support for a cache of information on each
meta_cb_num, which we can use to determine the size of a control block, as
given in udi_cb_init_t. This will be necessary for udi_cb_alloc().

Also added proper support for udi_enumerate_cb_t's UDI_DL_MOVABLE_UNTYPED
members. Specifically, we now allocate child_data and attr_list in libzudi.

* Began to add support for allocating the bind_cb for udi_channel_event_ind
  calls.
* Implemented udi_mem_alloc().
* Custom operators new()/delete() for fplainn::sMovableMemory.