Various clean up

Remove of_message_parse hack; just won't use it in message
objects for now.

Never rely on pack to calculate length of objects

Fix circular reference between eq and ne

Clean up some bad function references caught by test script
diff --git a/tools/munger/scripts/error_gen.py b/tools/munger/scripts/error_gen.py
index 9fce70d..0a6d241 100644
--- a/tools/munger/scripts/error_gen.py
+++ b/tools/munger/scripts/error_gen.py
@@ -14,12 +14,6 @@
 
 from ofp import *
 
-# This will never happen; done to avoid lint warning
-if __name__ == '__main__':
-    def of_message_parse(msg):
-        print "ERROR: of_msg_parse in error.py called"
-        return None
-
 """
 
 ################################################################
@@ -52,11 +46,12 @@
         self.header.length = self.__len__()
         packed = ofp_error_msg.pack(self)
         packed += self.data
+        return packed
 
     def unpack(self, binary_string):
         binary_string = ofp_error_msg.unpack(self, binary_string)
         self.data = binary_string
-        return []
+        return ""
 
     def __len__(self):
         return OFP_HEADER_BYTES + OFP_ERROR_MSG_BYTES + len(self.data)
@@ -64,12 +59,9 @@
     def show(self, prefix=''):
         print prefix + "--TYPE--_error_msg"
         ofp_error_msg.show(self)
-        print prefix + "data is of length " + len(self.data)
-        obj = of_message_parse(self.data)
-        if obj != None:
-            obj.show()
-        else:
-            print prefix + "Unable to parse data"
+        print prefix + "data is of length " + str(len(self.data))
+        ##@todo Consider trying to parse the string
+
 """
 
 error_types = [