Drop stats events when we get behind. Oh, and prioritise calls.
Don't drop reader stats ever, don't drop channel or queue stats from just before hibernation.
Merge default
Abandon call prioritisation, no longer convinced it's worth it with bug 23378 coming down the road (which will make it more important to process stats events and also make handling requests cheaper).
Before committing, it's traditional to make sure it compiles.
Merged default into bug24114
Merge bug24114 into default