Modified the private method uploadInMultipleParts() so each request to upload a part can recover from a network failure. Currently hardcoded to allow five retries per part.

The last exception generated by attempting an upload will be rethrown if the upload failed all five tries.

Does not add the part's checksum until after a successful upload, but will force a recalculation of the checksum on each try.

No logging is done in the class, but if logging is added, it would be nice to log these retries.
Merged in latest aws
First pass at making download job output public. Ended up moving the request to
get the archiveSize into downloadJobOutputInMultipleChunks() after the job completed, just to simplify the method. Not fully
tested yet
Merge pull request #60 from wolpert/master

Added retries to Glacier ArchiveTransferManager.uploadInMultipleParts()