This class is responsible for handling the pluggable
directives in VTL.
For example : #foreach()
Please look at the Parser.jjt file which is
what controls the generation of this class.
author: Jason van Zyl author: Geir Magnusson Jr. author: Kasper Nielsen version: $Id: ASTDirective.java 471381 2006-11-05 08:56:58Z wglass $
Sets the directive name. Used by the parser. This keeps us from having to
dig it out of the token stream and gives the parse the change to override.
Parameters: str -