deprecate or improve zipstream

New submission from kmike <None>:

As I can see the goal of zipstream is to provide support for an incremental approach to unzipping files. 

But standard zipfile has this support since python 2.6. ZipFile?.open() method returns file-like object which supports 'read' method with buffer size in parameters.

Implementation in zipfile is better than in zipstream. At least it works a lot faster because it don't have 'self.buffer = self.buffer[n:]' code which kills performance on big (even tens of Kb's) buffer sizes like zipstream version does.

I think is better to deprecate zipstream and copy implementation from new zipfile. Or make zipstream a backported zipfile wrapper.

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Type     : enhancement
Component: core
Keywords : 
Priority : normal
Nosy     : kmike
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http://twistedmatrix.com/trac/ticket/4035