[Automatic Bug Reporting Tool - ABRT] #776: implement global locks

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#776: implement global locks
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 Reporter:  mtoman  |       Owner:  crash-catcher@…
     Type:  defect  |      Status:  new
 Priority:  major   |   Milestone:  ABRT_server_release
Component:  faf     |     Version:
 Keywords:          |  Blocked By:
 Blocking:          |
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 (Needs some brainstorming)

Some faf-* scripts should only be ran once at one moment. As the scripts
 may run on different machines, locks should probably be implemented in DB.