obshash: resist to unknown revision during discovery

code movement: gather discovery code together The discovery code is the one thing that will survive the great purge.

bundle2: drop custom compat We'll rely on the core implementation to use bundle2.

drop relevant marker compat

evolve: always use the transaction version of phase movement This drop compat with all known released version of Mercurial.

evolve: drop debugobsoleterelevant Core gained this capability usig `hg debugobsolete --rev REV`

evolve: yield to relevant markers handling in core The handling of obsolescence marker is now performed in core. If we detect a mercurial with such power we skip the wrapping from evolve. This changeset also suffer from massive diff from the change in display of obsolescence marker with parent information introduced at the same time in core.

test-wireproto: adapt to output change from core

test: update test to new date formatting in debuobsolete output The date is now a first class citizen with proper formatting.

test: update help output to future 3.2

merge with stable

pkg: make tests pass using the generated tarball Exclude tests/test-drop.t and include tests/_exc-util.sh, tests/dummyssh, and hgext/simple4server.py.