Load management send slow down when close to limit

This is a copy of #248 with the two requested fixes added on top (255 as max byte and 65535 as max word).

The commits were actually made before I was aware of the new commit message rules, so the messages are still too long. Sorry about that…
We include extra information on e.g. peers, limits, but this is only used for logging; the stats are based on the fixed parts. So this is resolvable.