sync min requirements with allura min req
fix one issue with hg 7.2
support hg 6.8.2-7.1.2 with simplified better outgoing using hooks
actually suppress most hg stdout entirely (maybe later add a way for tests to show it)
remove unnecessary hg stdout handling for tests (pytest -s works fine to see stdout)
fix some deprecations and warnings
update configparser import to not use six
fix one issue with hg 7.2