(ebitset_size, ebitset_list, ebitset_list_reverse):

(ebitset_size, ebitset_list, ebitset_list_reverse):
Use bitset_bindex, not int or unsigned int or size_t, to count bits.

(ebitset_bytes): Use size_t, not unsigned int, to count bytes.

(struct ebitset_struct.size, ebitset_elts_grow,
ebitset_elt_add, ebitset_elt_remove, ebitset_weed,
ebitset_elt_find, ebitset_list_reverse, ebitset_list, ebitset_init):
Use bitset_windex instead of unsigned int.

(ebitset_elts_grow): Check for arithmetic overflow when computing sizes.