sess workspace.

is readable by the unprivileged user.

Fixes: #1072

Add a link to the varnishlog man page and the logging chapter in the tutorial

remove -i and -I, add -m and describe it. Simplify the docs. The user only needs to care about -m, really

allow intelligent hacking again:

Wrap lines longer than 80 char and fix inconsistent copy&paste in
copyright/disclaimer text.

I'm not sure if we should go into more detail about how the whole thing works

Minor improvements to a couple param-tweakers as consequence.

the initial guineapig.

We have a number of pools of objects we maintain dynamically and we
will get more in the future, so having a generic facility makes sense.

One particular aspect of some of our pools, is that the desired size
of object is variable over time, for instance workspaces which
depend on parameters etc.

Using generic code will allow us to use systematic parameters and
VSC stats for all pools, hopefully with some memory savings involved.

worker cache and a wrapper structure (needed for $param sized elements)
and two new stats counters.

backend related and will have somewhat complex semantics.

worker for now.

we will need it shortly.

Add more calls to them, they will also be needed shortly.