memmem, bytestring: Fix includes in _info

When I fixed up the includes in _info for nearly everything, I managed to
leave out a couple of my own modules.  This fixes them up.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
opt: always initialise values in set_llong_with_suffix()

The helper API functions based on set_llong_with_suffix() left the
value uninitialised in the case of an empty string argument. This is
quite unlikely to have caused problem in practice, as most values will
have already been set to a default and the non-NULL error message
should have triggered an early exit or some other emergency action.
Nevertheless, it caused a compiler warning on some minor version of
GCC 4.8 which I no longer seem to have, and the complaint seemed
reasonable at the time.

If an empty string (or any other non-numeric value) is passed to
strtoll(), the result is zero. As far as I know, the strtoll() call is
only short-circuited here to form a more specific error message, not
because there is a good reason for the empty string to be a special
non-initialising case. So let's set it to zero.

Signed-off-by: Douglas Bagnall <douglas@halo.gen.nz>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
opt: add an int decrementing helper function

opt_dec_intval decrements an int value, just as opt_inc_intval
increments.

There is not much more to say, other than it allows this
kind of thing, with balanced opposing options:

    static int opt_verbosity = 0;
    static struct opt_table options[] = {
            OPT_WITHOUT_ARG("-q|--quiet", opt_dec_intval,
                            &opt_verbosity, "print less"),
            OPT_WITHOUT_ARG("-v|--verbose", opt_inc_intval,
                            &opt_verbosity, "print more"),
            OPT_ENDTABLE
    };

which is an occasionally seen idiom.  It allows, e.g., people who like
quiet to use `alias foo='foo -q'`, while letting them get back to
normal and verbose modes with various amounts of '-v's.

Signed-off-by: Douglas Bagnall <douglas@halo.gen.nz>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
opt: Don't segfault if a string's default is NULL

Instead show '(nil)', like other people do. This is distinguishable
from a similar looking string value, because the latter is shown with
double quotes while NULL's nil has no quotes.

Signed-off-by: Douglas Bagnall <douglas@halo.gen.nz>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
tools/configurator: set HAVE_CLOCK_GETTIME even if it's in -lrt.

This avoids conflicts with autoconf and other config.h sources.

Based on the work by Cody P Schafer <dev@codyps.com>.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
time: update for new configurator.

HAVE_CLOCK_GETTIME_IN_LIBRT now implies HAVE_CLOCK_GETTIME.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>