Added middleware for digest authentication
Rework of the WWW_AUTHENTICATE header parsing

The previous method was failing in a lot of corner cases. This one is
able to withstand what I've thrown to it so far.
Example files for http digest auth

With both server and clients. I used WebRick for the server because it
comes standard with Ruby, and supports HTTP digest auth.
Basic specs for http digest auth
Fixed formatting

Added new lines at the end of files where needed.
Use EM::HttpEncoding instead of CGI
Don't force symbolization of the options keys
Refactoring of the parsing regexp to avoid additional string manipulation.
Adding gzipped file fixture that triggers issue igrigorik/em-http-request#204
manually extract the stream from gzip files to fix #204
Merge branch 'master' of github.com:elhu/em-http-request
Merge branch 'gzip' of github.com:martoche/em-http-request