JCLOUDS-597: HashCode methods for Content-MD5

This works more naturally with Guava Hashing methods and immutability
provides better safety guarantees.  Also deprecate existing byte[]
methods.
NodePredicates gained static predicate SUSPENDED
Replaced hard-coded Strings in toString methods of static predicates with their enum.toString counterparts
Added test 'testNodeRunningFailsOnSuspended'
Revert "Added test 'testNodeRunningFailsOnSuspended'"

This reverts commit 2a543bfe20540bb4f10ef4f86e845a63bdbe90e3.
Removed test 'testNodeRunningFailsOnSuspended'. Added test 'testNodeSuspendedReturnsTrueWhenSuspended'.
Renamed 'AtomicNodeSuspended.nodeRunning' to 'AtomicNodeSuspended.nodeSuspended'.\nWhere applicable combined all calls to 'replay(Object...)' instead of the old 'replay(node);replay(computeService);'
Merge branch 'master' of https://github.com/cdancy/jclouds