[Twisted-Python] Twisted cred perspective unicode support

[Brian Warner]

<rdrb at 123.cl> writes:

> I got problems using Twisted cred with Python2.2.0.
> My perspectives names are based on a url encoding.
> I have found that there is a problem when PerspectiveName is  unicode.

I've committed your fix into CVS, along with some new test cases. Thanks for
the patch!

I did some other s/types.StringType/types.StringTypes/ elsewhere in
twisted.cred.perspective too.

thanks,
 -Brian