MUSTFIX:
--------
* debconf gnome dosn't work (can't connect to the session)
  [ should be fixed with the bugfix on gksu ]
* display a message that all applications should be closed for the 
  dist-upgrade (and that strange things like a crashing panel can
  happen)
  [done in current dialog]


breezy->dapper
--------------
- gnome-icon-theme changes a lot, icons move from hicolor to gnome.
  this might have caused a specatular crash during a upgrade


hoary->breezy
-------------
- stop gnome-volume-manager before the hoary->breezy upgrade
  (it will crash otherwise)
- send a "\n" on the libc6 question on hoary->breezy

general
-------
- CDROM upgrades !!!

- whitelist removal (pattern? e.g. c102 -> c2a etc)?

- check authentication and don't upgrade anything that is not
  authenticated (maybe just comment unauthenticated stuff out?)


Robustness:
-----------
- automatically comment out entires in the sources.list that fail to 
  fetch. 
  Trouble: apt doesn't provide a method to map from a line in th
  sources.list to the indexFile and python-apt dosn't proivde a way to
  get all the metaIndexes in sources.list, nor a way to get the
  pkgIndexFiles from the metaIndexes (metaIndex is not available in 
  python-apt at all)
  What we could do is to write DistUpgradeCache.update(), check the
  DescURI for each failed item and guess from it what sources.list
  line failed (e.g. uri.endswith("Sources{.bz2|.gz") -> deb-src, get
  base-uri, find 'dists' in uri etc)
  
- don't stop if a single pkg fails to upgrade:
  - the problem here is apt, in apt-pkg/deb/dpkgpm.cc it will stop if
    dpkg returns a non-zero exit code. The problem with this is of course
    that this may happen in the middle of the upgrade, leaving half the
    packages unpacked but not configured or loads of packages unconfigured.
    One possible solution is to not stop in apt but try to continue as long
    as possible. The problem here is that e.g. if libnoitfy0 explodes and
    evolution, update-notifer depend on it, continuing means to evo and u-n
    can't be upgraded and dpkg explodes on them too. This is not more worse
    than what we have right now I guess.