Here's a patch which changes modsupport to add 'u' and 'u#',
to support building Unicode objects from a null-terminated
Py_UNICODE *, and a Py_UNICODE * with length, respectively.

[Conversion from 'U' to 'u' by Fred, based on python-dev comments.]

Note that the use of None for NULL values of the Py_UNICODE* value is
still in; I'm not sure of the conclusion on that issue.