Comment 25 for bug 893091

Looks like I am getting close. I reverted the 2.x version to inheriting from the correct string and number class (e.g. PyString and PyInt) and it passes the test suite. The 3.x has one more test it isn't passing in the standalone tests which has to do with guess_signature not handling the String (2.x) vs. Unicode (3.x) correctly. It is a bit of a messy change so I'm thinking about the best way to support both versions (e.g. two separate functions, a bunch of #if conditionals or macros).