[PATCH 0 of 2] graphlog: support --hidden

[Patrick Mezard]

This series should be appended to the one already posted here:

  http://selenic.com/pipermail/mercurial-devel/2012-February/038269.html

It implements --hidden in graphlog which means "hg log --graph" now
supports the same options than "hg log", and merging both can be
considered. See the wiki for more details (soon):

  http://mercurial.selenic.com/wiki/MergingGraphlogInCorePlan