(lbitset_size, lbitset_list, lbitset_list_merge):

Use bitset_bindex, not int or unsigned int or size_t, to count bits.

(lbitset_bytes): Use size_t, not unsigned int, to count bytes.
Use proper printf formats for widths of integer types.

(lbitset_ones, lbitset_not): Use bitset_windex instead of unsigned int.

(lbitset_elt_find): Simplify windex calculation and avoid cast to unsigned.