needs strategy for 'encoding' commits

[Jelmer Vernooij]

  affects bzr-git
  status triaged
  importance high

bzr-git should handle commits that have the encoding attribute set
properly.

Of course, the 'encoding' attribute should be honored where possible. If
it is unusual, we should store it in a bazaar revision property
somewhere so that we can set it again when decoding.

commits that originated in Bazaar should have the 'encoding' attribute
set to 'utf-8' and have all their data encoded accordingly.

existing commits in Git commits do not have a known encoding but ideally
they would be utf8. If an attempt to decode using utf8 does not work
we'll assume latin1.