tests/test-committer.out

prepush: add more precise error messages

Part of the patch is from [e-mail]

- indicate the branch name where there are multiple heads
- give better advice when hitting a possible race, where new heads are added
  between discovery and the call to branchmap(). In that case, asking the user
  to merge isn't helpful, since only remote has the changes.

changeset:   0:9426b370c206
tag:         tip
user:        My Name <[e-mail]>
date:        Mon Jan 12 13:46:40 1970 +0000
summary:     commit-1

changeset:   1:4997f15a1b24
tag:         tip
user:        [e-mail]
date:        Mon Jan 12 13:46:40 1970 +0000
summary:     commit-1

changeset:   2:72b8012b424e
tag:         tip
user:        foobar <[e-mail]>
date:        Mon Jan 12 13:46:40 1970 +0000
summary:     commit-1

changeset:   3:35ff3067bedd
tag:         tip
user:        [e-mail]
date:        Mon Jan 12 13:46:40 1970 +0000
summary:     commit-1

abort: no username supplied (see "hg help config")
No username found, using user@host instead
transaction abort!
rollback completed
abort: empty username!