Fix undefined behaviour (left shift of negative value) in long_hash.  Also, rewrap a line of length > 79, and update comments.
Fix undefined behaviour (left shift of negative value) in long_hash.  Also,
rewrap a line of length > 79, and update comments.

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator