cleanup: delete lots of unused local variables These were found by IntelliJ. There are many more, but these seemed pretty safe. Differential Revision: https://phab.mercurial-scm.org/D5629

localrepo: use context manager for lock and transaction in commitctx() Differential Revision: https://phab.mercurial-scm.org/D5624

localrepo: use context manager for locks in commit() Differential Revision: https://phab.mercurial-scm.org/D5623

localrepo: use context manager for transaction in commit() A side-effect is that the transaction is released a little earlier, so the "commit message saved in ..." messages now comes after the "rollback completed" message. That seems slightly better to me. Differential Revision: https://phab.mercurial-scm.org/D5622

commit: print "commit message saved in" message also if bookmark update fails The bookmark update is done within the same transaction, so if fails, the commit will also be rolled back. I just happened to notice this while messing with this code; we have not had reports of crashing bookmark updates from our users. The same applies to the clearing of the merge state, although I don't think that's currently tied into the transaction. Differential Revision: https://phab.mercurial-scm.org/D5621

remotefilelog: remove pointless return statement from constructor Differential Revision: https://phab.mercurial-scm.org/D5630

revset: support ranges in #generations relation

tests: fix module-import warnings in test-update-atomic.t These were caught by test-check-module-imports.t on Python 3. This should also make python3-buildbot green again. Differential Revision: https://phab.mercurial-scm.org/D5674

py3: use dict.items() instead of dict.iteritems() in tests/test-lfs-server.t dict.iteritems() is not present on Python 3. Differential Revision: https://phab.mercurial-scm.org/D5673

py3: add b'' prefixes in tests/test-lfs-serve.t # skip-blame because just b'' prefixes Differential Revision: https://phab.mercurial-scm.org/D5672