Include inherited members in the astdecl documentation tag

[Jesper Öqvist]

The @astdecl tag documents the JastAdd production for AST classes. It currently just prints the raw AST declaration, without inherited components.

For example, in ExtendJ the AddExpr has the following production:

AddExpr : AdditiveExpr;

The LeftOperand and RightOperand components are inherited from Binary via AdditiveExpr, but they are not visible in the documentation comment because they are not included in the @astdecl tag.

[Jesper Öqvist]

Improve AST productions in documentation comments

AST productions now include inherited components that were not explicitly declared in the JastAdd production.

fixes #288 (bitbucket)

→ <<cset bc9cb890f024>>