Don't unbusy failed objects, it is pointless and introduces a race.
Reserve h key for a future help screen

Move showing of debug counters from 'h' key to 'd' inside a running
varnishstat.
Helpful pointers for future contributors

Mostly an attempt at pointing people that send pull requests on Github
in the right direction.
Small example on how to do synthetic responses
Dump some info on fetch_objcore during panics
Try to close the #1449 race definitively.