Add ceph as blobstore via s3 api

This pull requests add support for configuring the Cloud Controller to use a non standard s3 endpoint.
The use case we have is using it to connect to piston ceph via the s3 api endpoint.
As can be seen in the screen shot below the blobs get successfully uploaded when pushing an application.
![blobs uploaded to ceph](https://f.cloud.github.com/assets/380697/1656146/537f0baa-5b6e-11e3-8291-7736bc1af193.png)