#3 Endless loop when loading XDOT files

[Michael Foetsch]

The XDOT format has been changed in some GraphViz
version after 2.2.1. When loading an XDOT file of the
new format, there is an endless loop in the mfGraph C++
code.

The workaround is to download and use GraphViz 2.2.1:
http://www.graphviz.org/pub/graphviz/ARCHIVE/graphviz-2.2.1.exe