Perl by default interprets + as a parameter prefix, which
means commands like `pct resize 103 rootfs +1G` error with
'Unknown option: 1g', we don't want that.
added 'extra-args' standard option
added 'extra-args' handling to PVE::JSONSchema::get_options
untainting 'extra-args' separately in RESTHandler::handle
The old code used string substitution for every line of the
input string, while perl can also iterate over all matches
via the /g re modifier, and can turn ^ and $ to act as
beginning/end of line via the /m modifier.
Effectively allowing a "match over all lines" via a simple
while ($data =~ /^.*$/gm);
The situation is a little different in SectionConfig because
there's a nested loop invovled which doesn't work with /g.
For this there are two options and I chose the safer one by
simply doing a split on newlines first.
The alternative would be to open the data as a
filehandle-to-string and use <$fh> to read lines, however
I'd have to throw in an eval{} to be sure to close the
handle afterwards.
spice-proxy used dns-name before which matches a combination of letters,
digits and dots, which happens to include ipv4 addresses but not ipv6
ones.
Since 'dns-name' sounds like it's only for names, I'm adding an address
format which is either a dns-name or an ip (including ipv6).
