how do I fix this header conflict?

[Benjamin Reed]

> b) try if some other flags combination works (-Werror
> -Wmissing-prototype ?)

OK, "-Werror -Wmissing-prototypes" instead of "-pedantic-errors" seems to
have the same behavior as current, but at least then I can pass
--disable-warnings on OSX and it configures properly.  Not really the best
solution but at least allows it to compile for me.  OK to commit?