Fix compression of certain binary files

This fixes an issue I'm seeing locally with compression of certain binary files.  For example, ZeroClipboard:
https://github.com/jonrohan/ZeroClipboard/blob/master/ZeroClipboard.swf
Merge pull request #34 from derekcicerone/master

Fix compression of certain binary files
Fix tests by listening on the correct streams
Open streams lazily to avoid too many open files. Closes GH-36.
Update to archiver 0.4.2.

Closes gh-38.
version bump