Adds Graphviz-based grapher extension

Adds grapher extension, an implementation for a Graphviz-based tool to
visualize an Injector. Main class is InjectorGrapher, which is available from
the GrapherModule. The GraphvizModule should also be installed for Graphviz

See for an example and to
generate a sample graph.

Fix for issue 213.

git-svn-id: d779f126-a31b-0410-b53b-1d3aecad763e
59 files changed