Extract line suppression logic.

Ulrich clearly has a very mathematical mind; I naturally write this in
terms of control flow, not binary ops.  Same effect, though.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Make --csv & --trim-outliers an error.

Warnings are too easy to miss, and this is a usage error which the user can
fix (unlike malformed inputs, which they might not have control over).

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

I thought 'this' was referring to l->pattern->part[i].type.

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