This is best-practice (to ensure prototypes match up), but there were a
few places we didn't (at least, directly). Make it a requirement,
either of form "foo.h" or <dir/foo.h>.
The noise is the change to our print templates.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We should actually be including this (as it may define _GNU_SOURCE
etc) before any system headers. But where we include <assert.h> we
often didn't, because check-includes would complain that the headers
included it too.
Weaken that check, and include config.h in C files before assert.h.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>