The new functions bitvec_get_bytes and bitvec_set_bytes copy
byte sequences from bitvecs to uint8_t arrays and vice versa.
While the bytes in the bitvecs do not need to be aligned, the uint8_t
arrays always are. In case the bytes in the bitvec are aligned, the
implementation uses memcpy.
Note that the implementation like the other existing functions assume
MSB first encoding.
[hfreyther: Squash the comment fix into this commit as well]
Sponsored-by: On-Waves ehf
Jacob Erlbeck