vztmpl-dl: add --quiet/--no-quiet

Add options (--quiet/--no-quiet) and a configuration parameter
(QUIET=yes/no) to shut wget output. Document in --help and in
a man page. Default is "no" (i.e. same as before).

https://bugzilla.openvz.org/2725

Reported-by: Pavel Odintsov <pavel.odintsov@gmail.com>
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
3 files changed