Implement '==' and '!=' for IP number variables (presently only client.ip)

Implement '==' and '!=' for IP number variables (presently only client.ip)

It works by building a one-entry ACL of the subsequent tokens
and matching this ACL just like '~' would have done.

This means that it is possible to use the '!', '(...)', '/width'
constructs and domain-names in these comparisons.

Examples:

	if (client.ip == ( "www.freebsd.org" )) {

	if (client.ip == (! "localhost" )) {

	if (client.ip == (! "10.0.0.0"/8 )) {

or even

	if (client.ip != "somehost" / 28) {

git-svn-id: svn+ssh://projects.linpro.no/svn/varnish/trunk@1389 d4fa192b-c00b-0410-8231-f00ffab90ce4