clearGraph in ICore, prio queue removed in IAlgorithm
Merge branch 'master' of
https://github.com/brugr9/ch.bfh.bti7301.hs2013.GraphVisualisierung2.git

Conflicts:
	GraphVisualisierung2/src/ch/bfh/bti7301/hs2013/gravis/core/algorithm/Dijkstra.java