JCLOUDS-417: Remove ConsumeOnCloseInputStream

ConsumeOnCloseInputStream can potentially perform a copy in finalize()
if the stream was not closed properly.
JCLOUDS-417: Test closing a stream w/o reading it
Enforce correct MD5 for local blobstores

Matches behavior of real blobstores.
Remove unneeded InputSupplier helper

Also convert byte[] to HashCode.
JCLOUDS-622: remove calls to InputSupplier methods

Guava 16 deprecated these methods and Guava 18 will remove them.