fixes ZEN-6981 make sure that lines still work with the cache restructuring reviewed by plu

git-svn-id: http://dev.zenoss.com/svnint/trunk/core@74140 f5df01ce-0320-0410-9ed9-ddcd13c732cc
* fixes ZEN-6082, add callhome interface for adding linked device counts; reviewed by empowell & jplouis.

git-svn-id: http://dev.zenoss.com/svnint/trunk/core@74144 f5df01ce-0320-0410-9ed9-ddcd13c732cc