* ChangeLog: For changes in doc/bison.texinfo, consistently reference

* ChangeLog: For changes in doc/bison.texinfo, consistently reference
node names: say "Table of Symbols" not "Bison Symbols", and say "Decl
Summary" not "Directives".
* doc/bison.texinfo (Decl Summary, Calc++ Parser): Cross-reference the
%code entry in "Decl Summary" rather than the one in "Table of Symbols"
since the former is now the more complete one.
(Prologue Alternatives): Likewise and do the same for %defines.
(Table of Symbols): Add summary of %code, add summary of %define, and
move full %code documentation to...
(Decl Summary): ... here for consistency with other entries in these
sections.
Move %define entry in order to keep this list alphabetized.
Reword %define entry a little to put less emphasis on the skeleton
concept, which most users shouldn't have to think about.