tests/test-empty-group.out

document and fix findincoming

- add documentation about what the function does, notably
  the fact that it updates 'base'
- transform the workflow to a more simple 'if elif elif else'
- do not call remote.branches if not necessary
- some nodes where missing in 'base' (from what I understand,
  if the root of a branch is missing but one parent is present,
  the parent should be in 'base')
- add a testcase for an incorrect outgoing that is fixed by
  this cset
- add a testcase for an empty group bug, it needs fixing

adding init
adding x
adding y
0 files updated, 0 files merged, 2 files removed, 0 files unresolved
adding x
adding y
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
requesting all changes
adding changesets
adding manifests
adding file changes
added 4 changesets with 3 changes to 3 files
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
requesting all changes
adding changesets
adding manifests
adding file changes
added 4 changesets with 3 changes to 3 files
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
searching for changes
changeset:   4:fdb3c546e859
tag:         tip
parent:      1:1f703b3fcbc6
parent:      2:de997049e034
user:        test
date:        Mon Jan 12 13:46:40 1970 +0000
summary:     m2

searching for changes
changeset:   3:f40f830c0024
parent:      2:de997049e034
parent:      1:1f703b3fcbc6
user:        test
date:        Mon Jan 12 13:46:40 1970 +0000
summary:     m1

searching for changes
changeset:   3:f40f830c0024
tag:         tip
parent:      2:de997049e034
parent:      1:1f703b3fcbc6
user:        test
date:        Mon Jan 12 13:46:40 1970 +0000
summary:     m1

searching for changes
changeset:   3:fdb3c546e859
tag:         tip
parent:      1:1f703b3fcbc6
parent:      2:de997049e034
user:        test
date:        Mon Jan 12 13:46:40 1970 +0000
summary:     m2

pulling from a
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 0 changes to 0 files (+1 heads)
(run 'hg heads' to see heads, 'hg merge' to merge)
pulling from a
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 0 changes to 0 files (+1 heads)
(run 'hg heads' to see heads, 'hg merge' to merge)