packaging: move most of contrib/docker to contrib/packaging/docker contrib/ is kind of a dumping ground for all kinds of random things. Many of the files in contrib/ are related to packaging. But sorting out how everything is related is a lot of effort since it is all mixed together. This commit starts the process of refactoring everything related to packaging so it all lives under one roof. Most content from contrib/docker is simply moved to contrib/packaging/docker and all references are updated. Differential Revision: https://phab.mercurial-scm.org/D3541

setup: reformat options argument This makes things a bit more easier to manage IMO. Differential Revision: https://phab.mercurial-scm.org/D3540

contrib: remove fixpax.py This was used as part of bdist_mpkg. And we stopped using bdist_mpkg after db5084d27df5. Differential Revision: https://phab.mercurial-scm.org/D3539

push: continue without locking on lock failure other than EEXIST (issue5882) This code was added by 3f5e75c22585 "push: make locking of source optional (issue3684)", but EACCES isn't the only error that could be triggered by filesystem permission. I think catching LockUnavailable is more appropriate than testing errno value by caller.

revlog: handle errors from index_node() in nt_insert() and index_slice_del() Same idea as in a9d9802d577e (revlog: don't say "not found" on internal error, 2018-05-04). Differential Revision: https://phab.mercurial-scm.org/D3558

help: add new deprecated topic Add a deprecated topic which lists most of the commands and options that are not recommended anymore.