Graph path + test refactor
Test refactor
graphtest
Graph Path Core

But not integrated into the main method
Graph bidirectional path finding

Some nodes that are not on the path still remains
Merge remote-tracking branch 'origin/master' into db-hibernate2

Conflicts:
	Data/src/main/java/cz/cuni/mff/ufal/textan/data/graph/Graph.java
	Data/src/main/java/cz/cuni/mff/ufal/textan/data/graph/GraphFactory.java