Don't optimize out the (completed) bo for esi-children
Fix a bug in setting *.ttl variables from VCL and go over
testcases at the same time.

Spotted by:	UPLEX
update gzip docs
fix a badly worded sentence, make choice of tense more consistent

Thanks to fgs for reviewing
fix errors and clarify that do_g* are ignored when gzip support is off
varnishd: streamline exit codes, fix exit codes for vsubs

This should bring us closer to the exit codes now documented in
varnishd.rst

Fixes #1572 for varnishd
tools: streamline exit codes, fix exit codes for vsubs

This should bring us closer to the exit codes now documented in
varnishd.rst

Fixes #1572 for tools
Fix a header name confusion

Thanks to dridi.boukelmoune@zenika.com for reporting.
Update names and examples for V4
Wording and whatnot

Also hide a might-be change until it's really implemented.