Improves Grapher's display of names:
 - Instances are now rendered with their #toString() if they're not the
   default Object implementation.
 - String instances are displayed as string literals.
 - ProviderMethods are rendered as a method signature.
 - Instance sources are now just rendered as the file name and line number.

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