Return "varnishd" for server.identity if no -i argument is given.

Wrap setproctitle() in mgt_util.c

But it should be available via VSM.

Otherwise the backend might see multiple Connection entries.
Fixes #2337.

If txrst is used without -err we want a valid error.
Spotted by msan.

Spotted by ubsan.

c00037.vtc already tests hash_always_miss.

In the section related to make test, the sentences were a bit hard incorrect. I've corrected it.

processes and therefore they are not trustworthy.

Retire vsc2rst

laster to get the memory/summing cost back down.

We don't optimize but emit straight C-code summing each element in
turn, so that it will work with any arithmetic C type down the road.