tests/test-commit-unresolved.t

discovery: drop findoutgoing and simplify findcommonincoming's api

This is a long desired cleanup and paves the way for new discovery.
To specify subsets for bundling changes, all code should use the heads
of the desired subset ("heads") and the heads of the common subset
("common") to be excluded from the bundled set. These can be used
revlog.findmissing instead of revlog.nodesbetween.

This fixes an actual bug exposed by the change in test-bundle-r.t
where we try to bundle a changeset while specifying that said changeset
is to be assumed already present in the target. This used to still
bundle the changeset. It no longer does. This is similar to the bugs
fixed by the recent switch to heads/common for incoming/pull.

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "graphlog=" >> $HGRCPATH

  $ addcommit () {
  >     echo $1 > $1
  >     hg add $1
  >     hg commit -d "${2} 0" -m $1
  > }

  $ commit () {
  >     hg commit -d "${2} 0" -m $1
  > }

  $ hg init a
  $ cd a
  $ addcommit "A" 0
  $ addcommit "B" 1
  $ echo "C" >> A
  $ commit "C" 2

  $ hg update -C 0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo "D" >> A
  $ commit "D" 3
  created new head

Merging a conflict araises

  $ hg merge
  merging A
  warning: conflicts during merge.
  merging A failed!
  1 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]

Correct the conflict without marking the file as resolved

  $ echo "ABCD" > A
  $ hg commit -m "Merged"
  abort: unresolved merge conflicts (see hg help resolve)
  [255]

Mark the conflict as resolved and commit

  $ hg resolve -m A
  $ hg commit -m "Merged"