log: do not display hidden changeset
We add a --hidden option to display them.
hidden: Add a hiddenrevs attributes to changelog.
This attributes hold the set of all revisions that should be ommited by command
and tools displaying changesets.
This set is given as a hit. Command and tools are responsible to check it in
order to filter they outpur.
Code adding revisions to the set are responsible to the consistency of it's
data.
config: handle comment lines in continuations (
issue2854)
http: report unexpected unparsable push responses (
issue2777)