Capture charts stack by collector, and go back a day

The capture chart told you how much was fetched but not by whom. Both charts are now stacked by collector, and hovering any bucket breaks it down - who fetched how many, and how many were rejected. Underneath it sits a second chart covering the last 24 hours in hourly buckets, which is where a collector that quietly stopped pulling its weight overnight becomes obvious. Empty stretches now draw as real zeroes instead of vanishing, so the time axis no longer lies about quiet periods.