* merged daniel burrows fixes for the auto-mark code

* merged daniel burrows fixes for the auto-mark code

Patches applied:

 * dburrows@debian.org--2005/apt--auto-mark--0--base-0
   tag of michael.vogt@ubuntu.com--2005/apt--auto-mark--0--patch-22

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-1
   doxygenize the new automark stuff

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-2
   Automatically update package markings after every state-changing public operation, and allow users of the dep-cache to group actions into a single action.

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-3
   Automatically update package markings after every state-changing public operation, and allow users of the dep-cache to group actions into a single action.

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-4
   Make action groups noncopyable

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-5
   Typo fix

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-6
   Add a FromUser flag to MarkKeep.

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-7
   Somehow the ActionGroup definition got duplicated; kill the duplicate.

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-8
   Cancel the automatic flag on packages that are being kept only if they are garbage.

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-9
   Don't clear the 'automatically installed' flag in MarkDelete.

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-10
   Add a FromUser flag to MarkInstall, and fix its handling of the Auto flag.

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-11
   Only clear the Auto flag on manual changes in MarkKeep.

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-12
   Make changes from the internal algorithms automatic.

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-13
   Use ActionGroups in algorithms that make lots of changes, and fix a compile error.

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-14
   Split the sweep code into a separate routine from pkgMarkUsed

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-15
   Update another call of MarkKeep to indicate that it's automatic.

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-16
   Move the mark-and-sweep code into pkgDepCache; call Sweep and document what it and Garbage are for; add a hook that can be used to generate a custom root-set function; move the big blob of regexp stuff into the custom root-set; fix the memory leak in the regexp stuff.

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-17
   Make ActionGroup take a reference instead of a pointer to the cache.

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-18
   Don't mark already-to-be-deleted packages as garbage, to imitate aptitude's behavior.

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-19
   Update apt-get for the new auto-mark protocol.

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-20
   Add a setter method for the Auto flag.

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-21
   Fix the test in apt-get about what to delete.

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-22
   Add a zero-argument mark-and-sweep routine and use it to do a mark-and-sweep on startup (so the garbage flags are initialized properly).

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-23
   Right, Status is 2 for new installs, not 0.

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-24
   POT updates.

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-25
   Actually initialize group_level to 0.

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-26
   Don't make an ActionGroup in Sweep, since there's no point and it also is an infinite loop.

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-27
   Add virtual hooks to control whether the garbage collector considers recommends and/or suggests to be strong links.

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-28
   Call the progress methods in the right order so we don't generate nonsensical progress notifications.

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-29
   Typo fix.

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-30
   Make RecommendsImportant default to true in apt, too.

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-31
   Add a release() method to action groups.

 * dburrows@debian.org--2005/apt--auto-mark--0--patch-32
   Add an 'autoremove' command that is synonymous to '--auto-remove remove'.