CASSANDRA-6091 – Better Vnode support in hadoop/pig

 Rewrite ColumnFamilySplit to contain multiple token ranges,
  and CqlPagingRecordRead to support it.

 After all splits have been fetched (or "described")
  group them by "dataNodes", sort them by startToken,
  and collapse them together permitting split size.

temporary: ColumnFamilyInputFormat + ColumnFamilyRecordReader removed for testing sake.