Using the graphstream project to layout the graph
Merge branch 'master' into CLI

Conflicts:
	graphwalker-webrenderer/src/main/java/org/graphwalker/webrenderer/geometry/Edge.java
	graphwalker-webrenderer/src/main/java/org/graphwalker/webrenderer/geometry/Label.java
	graphwalker-webrenderer/src/main/java/org/graphwalker/webrenderer/geometry/Point.java
	graphwalker-webrenderer/src/main/java/org/graphwalker/webrenderer/geometry/Vertex.java
	graphwalker-webrenderer/src/main/java/org/graphwalker/webrenderer/geometry/layout/SpringEmbedder.java