codetools: TPointerToPointerTree based on TAVLTree

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@42724 4005530d-fff6-0310-9dd1-cebe43e6787f
codetools: TUsesGraph.FindShortestPath

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@42725 4005530d-fff6-0310-9dd1-cebe43e6787f