Support standard S3 connection URIs

[alokwatve]

S3 writes work when the region is part of the URL e.g., The following URL works: https://s3.us-east-1.amazonaws.com?sa=D&source=docs&

However, when S3 region is specified in the options, the write fails: https://s3.amazonaws.com?region=us-east-1&sa=D&source=docs&<more_options>

As far as we know both the ways are valid for S3 access.