py3: replace file() with open() in test-mq-qimport.t file() is not present in Python 3. Differential Revision: https://phab.mercurial-scm.org/D2120

py3: replace file() with open() in test-patch-offset.t file() is not present in Python 3. Differential Revision: https://phab.mercurial-scm.org/D2119

py3: replace file() with open() in test-relink.t file() is not present in Python 3. This patch also adds a b'' prefix to make sure we write bytes in Python 3. Differential Revision: https://phab.mercurial-scm.org/D2118

py3: replace file() with open() in test-subrepo-missing.t file() is not present in Python 3. This patch also adds a b'' prefix to make sure we write bytes in Python 3. Differential Revision: https://phab.mercurial-scm.org/D2117

py3: replace file() with open() in test-tag.t file() is not present in Python 3. Differential Revision: https://phab.mercurial-scm.org/D2116

py3: replace file() with open() in test-transplant.t file() is not present in Python 3. This patch also adds a b'' prefix to make sure we write bytes in Python 3. Differential Revision: https://phab.mercurial-scm.org/D2115

py3: replace file() with open() in test-walk.t file() is not present in Python 3. This patch also adds a b'' prefix to make sure we write bytes in Python 3. Differential Revision: https://phab.mercurial-scm.org/D2114

py3: replace file() with open() in test-win32text.t This patch also adds b'' prefix to make sure we write bytes on Python 3. Differential Revision: https://phab.mercurial-scm.org/D2113

py3: replace file() with open() in test-convert-p4-filetypes.t file() is not present in Python 3. While I was here, I added b'' prefix to make sure we write things correctly in Python 3. Differential Revision: https://phab.mercurial-scm.org/D2112

py3: replace file() with open() in test-convert-mtn.t While I was here, I added b'' prefixes to make sure we write things correctly in bytes mode on Python 3. Differential Revision: https://phab.mercurial-scm.org/D2111

py3: replace file() with open() in test-clone.t While I was here, I made sure we write things correctly in bytes mode. Differential Revision: https://phab.mercurial-scm.org/D2110

merge: cut import cycle at merge -> extensions This seems less bad because checking fsmonitor looks like a temporary hack, and cmdutil -> mergemod should be a valid dependency.

subrepo: split non-core functions to new module Resolves import cycle caused by subrepo -> cmdutil. Still we have another cycle, cmdutil -> context -> subrepo, but where I think importing context is wrong. Perhaps we'll need repo.makememctx().

diff: remove fp.write() wrapper which drops label argument It's no longer needed since we've split labeled write() from file-like write().

log: pack filematcher and hunksfilter into changesetdiffer object This is just a way of getting rid of clumsy makefilematcher/makehunksfilter arguments. There might be a better abstraction, but I don't think this is bad. This makes filematcher and hunksfilter available by default, but that should be fine.