visualization adapter

[John Sichi]

Nice...someone combined our jgrapht-guava adapter with code ported from JUNG to create more visualization support:

https://github.com/tomnelson/jungrapht-visualization

There's some overlap with our new drawing component, but it's good to see a variety of flowers blooming organically :)

[Dimitrios Michail]

Good news.

They support our graph interface and thus also the guava ones.

The Jung visualization layer also has controls, listeners, etc.  We are only adding the algorithmic part.