Work around CloudFiles test failures

Java helpfully interprets Expect: 100-continue instead of returning
the response code.  This commit reverts
100afba1d8b2d1a440168fed271a7b39ab0152e7.
Return false if container already exists in AWS-S3

AWS-S3 returns the incorrect creation status when a container already
exists in the us-standard (or default) region.  Fixes JCLOUDS-334.