Fixes the regression caused by HADOOP-17511 by moving where the
option fs.s3a.acl.default is read -doing it before the RequestFactory
is created.
Adds
* A unit test in TestRequestFactory to verify the ACLs are set
on all file write operations.
* A new ITestS3ACannedACLs test which verifies that ACLs really
do get all the way through.
* S3A Assumed Role delegation tokens to include the IAM permission
s3:PutObjectAcl in the generated role.
Contributed by Steve Loughran
Change-Id: I3abac6a1b9e150b6b6df0af7c2c70093f8f518cb
c1ad91e72d