This is a relatively simple change and is faster.

I do not understand the insides of the ZipArchive well enough to see why
the additions to  RWBinaryOrTextStream are included, but it seems fine.

Recommend that this be included.













< I'm a bug-fixing machine! >

This post brought to you by the BugFixArchiveViewer, a handy tool that
makes it easy to comment on proposed fixes and enhancements for Squeak. 
For more information, check out the Web page for the BugFixArchiveViewer
project: http://minnow.cc.gatech.edu/squeak/3214 

< I'm a bug-fixing machine! >