Fixes	#1211

Thanks to:	Federico G. Schwindt

POLLHUP is always checked for, and is output-only on Linux and OSX, so
avoid putting it in the list of events we check for.

architectures.

NB:  VMOD writers need to review/revise use of the INT type.

Fixes #1204

way any stevedore interested in new bans can request to be notified
(not just the persistent).

Also report dropped bans to the stevedores.

signal background threads to stop in preparation for the coming close
callback.

allocation calculations.

This then also breaks the previous expectation that cur_seg would
always be non-NULL. Change the code to take this into account.

Fixes: #1146

smp_copy_signspace() will copy the sign data of one space onto another.

smp_trunc_signspace() will truncate the signed space to len bytes and
resign the space.

growing signed data structures.

build happy on FreeBSD.

This should not have any impact on the "normal" deliveries, as these
will as before be done through a single writev operation.

For deliveries involving chunked encoding (e.g. ESI or gunzip), this
should prevent an unnecessary delay where the Nagle algorithm kicks in
on the end-chunk write. This should give higher throughput and better
utilization of a single connection, especially for clients not doing
pipelining.

buy 512TB ram to run Varnish on ppc64.

Separate out the text describing the storage backends so it can be resued in both the man page and users guide

Some of them are rather pedantic:  "NULL" vs "(char*)0" -- Really ?