Unicorn 0.991.0 - startup improvements

Unicorn is an HTTP server for Rack applications designed to only serve
fast clients on low-latency, high-bandwidth connections and take
advantage of features in Unix/Unix-like kernels. Slow clients should
only be served by placing a reverse proxy capable of fully buffering
both the the request and response in between Unicorn and slow clients.

Changes:

The “working_directory” configuration parameter is now handled
before config.ru. That means “unicorn” and “unicorn_rails” no
longer barfs when initially started outside of the configured
“working_directory” where a config.ru is required. A huge
thanks to Pierre B. for catching this ugly UI inconsistency
before the big 1.0 release

Thanks to Hongli L., out-of-the-box Rails 3 (beta) support
should be improved for deployments lacking a config.ru

There are more new integration tests, cleanups and some
documentation improvements.