Omit minlen parameter in dot graphs, since it causes xdot to crash (without error message)

generator/analysis/common.py

@@ -215,7 +215,10 @@ class Edge:
     def dump_as_dot(self, within={}):
         ret = ""
         attrs = {
-            "minlen": 3,
+            # omit minlen parameter, since it causes dot to crash (without an
+            # error message) for some larger graphs. The parameter would cause
+            # graphs to look nicer due to the minimum distance between nodes.
+            # "minlen": 3,
             "label": '"' + str(self.label) + '"',
             "color":self.color,
         }