updated changelog

Author: agroszer

Changelog

@@ -8,8 +8,11 @@ Unreleased:
 
 Enhancements:
 	New location, and new main maintainers.
-	Various fixes and improvements to the Makefile and testrunning.
+	Various fixes and improvements to the Makefile and test running.
 	Automatic tests and coverage of master and pull request with Travis and Coveralls.
+    Make shortest_path (Dijkstra's algorithm) run in O(E log V) instead of O(E^2) (dkorduban)
+    Make graph.add_edge run in O(1) instead of O(degree(V)) (dkorduban)
+    Added implementation of Kruskal's Minimum Spanning Tree construction algorithm (goldragoon)
 
 
 Release 1.8.2 [July 14, 2012]