Adds a configuration directive that will be parsed for every catalog.cfg
file.
Accepts three parameters -- the name of the directive, the name of the parser (if any), and the default value (if any). The following definition would add a directive ``Foo'', with parser ``parse_bar'', and a default value of ``Hello, world!'':
AddDirective Foo bar "Hello, world!"
If the parser is not defined, the directive value will be scalar and the
same as what the user passes in the config file. If defined, the parser
must be extant before it can be referenced, is always resident in
Vend::Config, and begines with the string parse_; the above example would use. Examples can be found in the files in the
distribution software directory compat/.