Update the script for batch processing of copyright messages so that
it can add new copyright messages in addition to replacing existing
copyright messages.

Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Change-Id: I4d8fe306da7444e9d75214e9fc314a42f4aef345
Reviewed-on: http://review.whamcloud.com/2241


Tested-by: Hudson
Reviewed-by: Minh Diep <mdiep@whamcloud.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>