Support using profile-based credentials for S3 binary storage

[dalbani]

https://issues.jboss.org/browse/MODE-2693

[hchiorean]

this looks good, but requires at least 1 unit test to validate the enhancement (see https://github.com/ModeShape/modeshape/blob/master/modeshape-jcr/src/test/java/org/modeshape/jcr/value/binary/S3BinaryStoreTest.java) for standalone repositories and 1 unit test for the JBoss AS subsystem (see https://github.com/ModeShape/modeshape/blob/master/deploy/jbossas/modeshape-jbossas-subsystem/src/test/java/org/modeshape/jboss/subsystem/ModeShapeConfigurationTest.java#L129)

In the 2nd case, it should be as simple as adding a 2nd repository without a user-name and password to https://github.com/ModeShape/modeshape/blob/master/deploy/jbossas/modeshape-jbossas-subsystem/src/test/resources/org/modeshape/jboss/subsystem/modeshape-s3-binary-storage.xml

[dalbani]

@hchiorean
I will a new entry in modeshape-s3-binary-storage.xml then.
But I don't really see how I'm supposed to alter S3BinaryStoreTest.java to test the profile credentials feature. Any idea?

[hchiorean]

@dalbani I didn't see that that S3BinaryStoreTest mocks everything... in this case I doubt a test would really be useful.

So just the test for the AS subsystem is ok.

[dalbani]

Test entry added.

[hchiorean]

please squash the 2 commits; everything else looks fine

[dalbani]

Squashed.