Replace copied code in pricklepit.c dictview_new

[akruis]

pricklepit.c contains a copy of _PyDictViewObject and _PyDictView_New. Unfortunately _PyDictView_New was changed (2eea952) and now the copy is out of sync. An assertion failure is the outcome. Theses copies were required in previous versions of Stackless, when the original definitions had a "static" scope.

I'll replace the copied code and use the original definitions.

[akruis]

Not relevant for 2.7-slp, because Stackless 2.7 can't pickle dictviews.