Makefile.am: Disable a big set of bison warnings

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
configure.ac: Remove the bison check

The bison check was inflexible and buggy, removed. If any platforms
break because of this, I'll add more documentation to point at needing
bison.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>