The varnish-counters man page looked so sad for the
counters without long descriptions. Not there yet, but a step
on the way.

In the long description we have sufficient room to
use the full word.

Submitted by:	Muhammad Adeel via github

Found by:   Geoff

Source data from file time on repo.varnish-cache.org.

Fixes: #1349

Trivial test VCL:

	C{ }C; vcl 4.0;

system size

This is to spot obvious typos

in play in a way that does not lead to panics.

Spotted by:	Martin
Fixes		#1607

Make the help text for the VSC counters a bit more explanatory.

Fixes: #1610

Spotted by: coredump

Writing to bereq.uncacheable in backend_response and backend_error would only
make sense in the context of a retry. In most real world cases, writing to
be*resp*.uncacheable would be intended in backend_response and backend_error.