Types of locking situations
   1. Concept map is locked
   1. Concept map is read only
   1. Concept map is locked, but concept to edit is a part of a CM locked by another user
   1. Concept is viewed in the Vertex viewer
   1. Concept is edited in InfoItems cockpit


Lock policies
   1. One is not allowed to edit concepts in a read only CM (only view properties)
   1. One is not allowed to save a CM/change CM properties for a read only CM
   1. One is not allowed to edit concept properties if the concept is locked by another user (or the same user has open 2 edit dialogs for the same concept in different CMs)
   1. One is allowed to add relations to a concept locked by another user
   1. One is allowed to edit an unlocked concept that is in a CM locked by another user
   1. CMs should get a flag "dirty" if a concept in it was changed by another source (e.g. in a infoItems cockpit or VV)
      1. User has to get a signs that concepts were changed
         1. e.g. some symbol displayed as a concept icon
         1. If user opens such a concept it has to be refreshed from the server
         1. Flex-application should send "refresh"-requests periodically to get informed about changed concepts