Auth v4 canonical request

[alexandre-merle]

The computation of the canonical request should normalize the request path, like this

GET /example/.. HTTP/1.1
Host:example.amazonaws.com
X-Amz-Date:20150830T123600Z

should result in :

GET
/

host:example.amazonaws.com
x-amz-date:20150830T123600Z

host;x-amz-date
e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855

This fix need to be done against rel/6.2

Note: This behavior is not use for s3 requests, but every other services

[LaurenSpiegel]

Very important -- any normalizing should NOT be used for requests to S3.

In exception to this, you do not normalize URI paths for requests to Amazon S3. For example, if you have a bucket with an object named my-object//example//photo.user, use that path. Normalizing the path to my-object/example/photo.user will cause the request to fail.