and always set it in varnishtest

Spotted by: scn

vary length

also work.

Spotted by Kristian.

two private members.

Check the now miniobj-ified structs from VCC.

takes effect.  Use this to move backend probes as appropriate.

This also retires the vbc_mempool, which doesn't seem to improve things.

Spotted by Coverity.

malloc space: we leak memory while we collapse.

This updates the last oustanding document to 4.0

as appropriate.

we can avoid thundering-herd/resonance phenomena when we have multiple
waiters.

Spotted by fgs.

Also req_flags.h was originally made in 2015, not 2014.

Various other cleanups while here.

There are a couple of central things I do not understand about how
this works, if anybody has epoll(2) clue, please contact me.

Copyright statement is updated according to the year of the
last non-trivial change to the file.