JCLOUDS-457: BlobStore MultiPartUpload strategy

The code related to the MultiPartUpload strategy has been added.
MultiPart uploads use an upload strategy (e.g. sequential vs parallel)
and also a slicing strategy to split the payload in different parts.
JCLOUDS-457: Long live tests

The long live tests have been added. These tests takes several
hours and will leave traces in your AWS account.
JCLOUDS-457: List containers and remove blob

List containers and remove blob operations have
been added.
JCLOUDS-457: Add polling strategy

The polling strategy interface for job operations
and a simple implementation class have been added.
This implementation waits an initial time and then
polls at regular intervals.
JCLOUDS-457: Add getBlob operation

Now the BlobStore abstraction supports the getBlob Operation
JCLOUDS-457: Add list operation

Now the BlobStore abstraction supports the list Operation
JCLOUDS-457: Add blobExists and blobMetadata

Now the BlobStore abstraction supports the blobExists and the
blobMetadata operations.
JCLOUDS-457: Add Clear vault strategy

Added a proper implementation to the Clear vault strategy