merge: fix wrong number of arguments for bid merge message

--HG--
branch : stable
tests: better test coverage for bid merge

Martin Geisler's test case revealed the previous message argument error.

--HG--
branch : stable
extra : amend_source : 0b4d5a3f06add2e274e00ddf69e301ba26d05147
merge: fix stray character in bid merge message

--HG--
branch : stable
merge: tell the user when we are using bid merge

Bid merge is a new rarely used feature that the user explicitly enabled - we
should tell/warn when the user actually is using it, just like we tell when we
not are using it.

Give a message like
  note: merging 3b08d01b0ab5+ and adfe50279922 using bids from ancestors 0f6b37dbe527 and 40663881a6dd

--HG--
branch : stable
merge: improve notes for listing the bids for ambiguous merges

--HG--
branch : stable
revset, i18n: add translator comment to "only"

--HG--
branch : stable
commands: fix typo in --graph description

--HG--
branch : stable
histedit, i18n: replace '+' with concatenation to make hggettext happy

--HG--
branch : stable