Test using a bit vector for storage instead of bytes

[PatrickCronin]

In the bitslice-based implementation, bits are stored in []bytes, with each byte in the slice storing either a 0 or a 1. Each bitslice is therefore taking up 7 times more space than necessary.

In this branch we try implementing a vector/slice of bits, where bits are still stored in []bytes, but a byte holds 8 bits.

Preliminary results show that the bitslice-based implementation, while massively inefficient in its storage, is faster than the bit vector approach, by almost 2 orders of magnitude.