py3: use hex(hasher.digest()) .hexdigest() returns a system str. .digest() consistently returns bytes. Differential Revision: https://phab.mercurial-scm.org/D2159

py3: use string for "close" value in commit extras The extras dict on commits has string keys and values. Before this commit, we passed "close" as an integer, which Python 2 gladly coerced to a string during a %s formatting in the bowels of changelog.py. Differential Revision: https://phab.mercurial-scm.org/D2157