EclipseGraphviz gets an update site

A few people have asked for a more convenient way of getting EclipseGraphviz other than by checking it out from the Subversion repository on Sourceforge, so I decided to create an update site with the most current code. Again, this is alpha code, so proceed with caution.

Check out the EclipseGraphviz wiki on instructions for installing EclipseGraphviz from the update site and a few hints on how to use it.

Enjoy. Feedback is most appreciated.