agreeing on dcbActor instance name

We need to agree on dcbActor instance name.

ccdActor is expecting dcb_%(specName)s, but it always has been named dcb here.

For that reason, some data taken recently has header issues ( eg W_PFDSGN is missing ...)

I'm not against dcb_%(specName)s, but i'm not sure to see what are we gaining.