* src/graph/graph_clustering.cc
  * src/graph/graph_distance.cc
  * src/graph/graph_extended_clustering.cc
  * src/graph/graph_distance_sampled.cc
* fixed "jacknife" variance bug in src/graph/graph_clustering.cc



git-svn-id: https://svn.forked.de/graph-tool/trunk@97 d4600afd-f417-0410-95de-beed9576f240