Support delete

[fengmk2]

/**
 * Deletes all the KeyValues that match those found in the Delete object,
 * if their ts <= to the Delete. In case of a delete with a specific ts it
 * only deletes that specific KeyValue.
 * @param regionName region name
 * @param delete delete object
 * @throws IOException e
 */
public void delete(final byte[] regionName, final Delete delete) throws IOException;

[fengmk2]

@coolme200 work for this issue.