Add LEVEL #4 regression testing files which is dedicated to
VTC files in relation with bugs they help to reproduce.
At the date of this commit, all VTC files are LEVEL 4 VTC files.
With certain curl versions URLs which contain brackets may be interpreted
by the "URL globbing parser". This patch ensures that such brackets
are escaped.
Thank you to Ilya Shipitsin for having reported this issue.
Ilya Shipitsin reported that with some curl versions this reg test
may fail due to a wrong URI syntax with ::1 ipv6 local address in
this varnishtest script. This patch fixes this syntax issue and
replaces the iteration of "procees" commands by a "shell" command
to start curl processes (must be faster).
Thanks to Ilya Shipitsin for having reported this VTC file bug.
