* data/m4sugar/m4sugar.m4: Update from CVS Autoconf.

* data/m4sugar/m4sugar.m4: Update from CVS Autoconf.
* data/bison.simple, data/bison.c++: Handle the `#define' part, so
that we can move to enums for instance.
* src/output.c (token_definitions_output): Output a list of
`token-name, token-number' instead of the #define.
(output_skeleton): Name this list `b4_tokens', not `b4_tokendefs'.