DP-205 Forward merging HADOOP-3733 and HDFS-4505

Merged patches for HADOOP-3733 and HDFS-4505

Squashed commit of the following:

commit df873eb3e5179d2c80682548285996dd59e735c3
Author: Abin Shahab <ashahab@altiscale.com>
Date:   Wed Nov 13 16:13:58 2013 -0800

    HADOOP-3733 AE-173 patch forward merged to 2.0.5

    "s3:" URLs break when Secret Key contains a slash, even if encoded
    Done as part of DP-205

commit 1d5dcae8eac4264e72ccdaa14668a9d4223ea4a5
Author: Abin Shahab <ashahab@altiscale.com>
Date:   Wed Nov 13 16:07:53 2013 -0800

    HDFS-4505 OPS-744 patch forward merged to 2.0.5