merge: coerce nodes to bytes, not str Differential Revision: https://phab.mercurial-scm.org/D2250

py3: whitelist more passing tests I had some good success tonight with histedit tests. test-histedit-fold.t is now low-hanging fruit: it is only failing because the logic for setting environment variables in hook.py is slightly busted. Specifically, hook.py line 142 should be making sure it puts strings in the env dict, not bytes, to avoid b'' goo in environment variables. Differential Revision: https://phab.mercurial-scm.org/D2249

histedit: binascii.unhexlify (aka node.bin) throws new exception type on py3 Lucky for us, the exception type exists on 2.7, so we can include it in the except block without any extra work. Differential Revision: https://phab.mercurial-scm.org/D2244