default destination keyspace is lower case.
better logging
validate differently. We only care that the dest is a superset of source.
More verification tweaks.
 * OperationTimeoutException warrants a long pause and shouldn't count against the tries.
 * Sleep 1s before each verification.
 * Validate only the intersection of sets. (this removes the possibility of ttl).
 * Blow up if there are a great deal more things in the source than the dest (indication that things weren't copied).
All another version of migration tool to migrate non-numeric CFs