Merge pull request #3 from timborden/3.2/master

Updating vendor AWS-SDK.
Adding listing support.
Updating AWS-SDK.
Updating Rackspace Cloud Files SDK.
Added "certificate_authority" config option for S3 driver.
Updating Cloud Files SDK to support subdirectories.
Updating Cloud Files submodule reference.
Upgrading EMC Atmos SDK to 1.4.1.21
Updated readme and changelog.
Adding support for transparently extending. Renamed `Storage_Listing` to `Storage_Listing_Abstract`.
Removing module init as it is no longer needed (since AWS SDK upgrade). Updating docs.
Cleaned up api in prep for 0.4.0.
Updated user guide.
Updated FTP driver to use `Storage_Exception`. Updated changelog in prep for releasing.
Resolving issue #4 relating to FTP SSL option.
Resolved issue #5 relating to pass by reference on `classes/storage/listing/abstract.php#L127`.
Resolved issue #6 adding `path_style` option to S3 driver.
Renamed class files and directories to support PSR-0.
Updates to basic formatting.
Updated basic formatting.