Suppress graphstream outputting edge positions on visualization request

[MaxKissgen]

Graphstream seems to always output every chosen position for every edge of a graph to console for the SVG visualization. While this isn't really a problem for smaller graphs (and maybe no problem with disabled output for WebOCD?), this can highly increase the response time for returning a graph visualization for bigger graphs since all those individual print statements will first be executed before the visualization is returned.

So far I think the only way to combat this is to make changes to the graphstream code and therefore create an own jar.