Zip handled by Ionic.Zip. Can read from file system but not from web.
Modified unit test to create memory stream if zip stream is not seekable.
Modified project to use SharpZipLib
All unit tests now pass.
Changed how unseekable streams are handled. It used to copy the whole zip archive stream to a memory stream. Now a more efficient method is used (ZipInputStream).
Merge pull request #3 from WSDOT-GIS/use-SharpZipLib

Use sharp zip lib to allow pre-.NET 4.5 support