important when a built failed in between.

* re-import DoD configure funcationlity

- fixed comment

- add baserev in link
- automatically set baserev in keeplink case

- fixed query parameter handling of diff command

- add "emptylink" query flag to make osc repairlink easier
- fix package copy if to source is an expanded link

- removed arbitrary heuristics from enabled()

  * changed logic for enabling/disabling build targets. Now it supports
    constructs like:
    <build>
      <enable repository='openSUSE_10.3'/>
      <disable/>
    </build>
    Additionally all packages inherit the project wide build target settings
    and may override them.
  * this should fix #493892 ("Problems to enable build in single reporistory only")
  * question: why does the srcserver care about the disable/enable stuff at all?
    Wouldn't it be more appropriate if this task is dedicated solely to the
    scheduler (even if the srcserver might read the deps for unneeded repos)?
- enabled():
  * the arch attribute has a higher score/exactness than all other attributes
    (repository).

- removed random filter in script/import
- thanks to jon nelson and michael e. brown for reporting this