Fix contrib/cube and contrib/seg to build with bison 3.0.

These modules used the YYPARSE_PARAM macro, which has been deprecated
by the bison folk since 1.875, and which they finally removed in 3.0.
Adjust the code to use the replacement facility, %parse-param, which
is a much better solution anyway since it allows specification of the
type of the extra parser parameter.  We can thus get rid of a lot of
unsightly casting.

Back-patch to all active branches, since somebody might try to build
a back branch with up-to-date tools.