Save buckets and objects filenames with url encoded characters properly

Each controller in its constructor set `env['PATH_INFO']` which is a variable that will be used by [swift.common.swob.Request](https://github.com/openstack/swift/blob/master/swift/common/swob.py#L798) object to know the path requested by the client. `swob.Request` expects this value not to be unquoted (because path property applies `urllib2.quote()` to return it)

So, right now, if we try to create (e.g.) a bucket with characters that must be url encoded (like spaces or any non-ascii char), the bucket will be created quoted.

The issue is easy to reproduce and verify when you combine horizon front end with another s3 library