IdealGraphVisualizer: work around a Swing/NetBeans tree UI problem that occurs when mouse events are handled while the tree model is changing, e.g. when using IGV while it still receives graphs from a compiler. BasicTreeUI attempts to get the boundaries for the node associated with the location on screen, but fails and tries to access a null Rectangle, causing a user-visible NullPointerException. By implementing equals() for GraphNode, nodes for graphs that are already in the tree are not removed and re-added when updating groups, and the exception can no longer be reproduced. This potentially also resolves some redraw issues.

README:
  This file should be located at the top of the hotspot Mercurial repository.

  See http://openjdk.java.net/ for more information about the OpenJDK.

  See ../README-builds.html for complete details on build machine requirements.

Simple Build Instructions:

    cd make && gnumake
     
  The files that will be imported into the jdk build will be in the "build"
  directory.