added missing system package for open ssl's dev libs

added missing system package for open ssl's dev libs, you can't install pip requirements without them installed.
Implemented parallel pull
Switch the io buf size to 128kB instead of 64
disabling new-relic
Close the duplicated key when the chunk transfer is complete
Fixed warning
Fixed gunicorn restart
Improve parallel key. Spend less time on the buffering mechanic
Merge pull request #86 from kencochrane/master

added missing system package for open ssl's dev libs
Reduce concurrency to 20
Improved logging
Bumped version to 0.6.1
Fixed pep8
Merge pull request #89 from dotcloud/fast-s3

Fast s3
Fixed typo
lib/s3: switching a warning to error
Update README.md
Merge branch 'master' of https://github.com/dotcloud/docker-registry