This operator defines the name(s) of diagrammer(s). It is followed by a list
of string separated by blanks.
This operator should only appear in a diagram header block.
\diagrammer("John Montroll");
\diagrammer(NAME_STRING);
NAME_STRING
Description : Indicates the model author name string.
Type : String.
Allowed values : Any well formed string (between two double-quotes (")).