Fix for errors that call objRefSplit() for args

[jasonhildebrand]

We recently upgraded from an old version of Webware to the current master.
We discovered that there are some bugs in two cases where objRefSplit() is called, and the results are used to raise an exception. These bugs were not present in the old Webware version - they must have been introduced more recently.
This PR fixes both cases. We searched but did not find other occurrences of this bug in MiddleKit.

[Cito]

Well spotted, Jason! The code actually looked like this in the very old versions:

raise ObjRefZeroSerialNumError, objRefSplit(objRef)

When this was converted to the more modern and readable comma-less code, the second object (the tuple returned by objRefSplit) was used as the argument for the error class, but it should be the argument list, as explained in the language docs. Thanks for reporting this subtle problem. I would not have noticed, since I don't use the MiddleKit.