Support multiple origin

[Salamandar]

Some files have this kind of content:

$ORIGIN .
$TTL 10 ; 10 seconds
main.tld.            IN SOA  ns0.main.tld. hostmaster.main.tld. (
                753318     ; serial
                10800      ; refresh (3 hours)
                3600       ; retry (1 hour)
                604800     ; expire (1 week)
                10         ; minimum (10 seconds)
                )
$TTL 3600   ; 1 hour
            NS  ns0.main.tld.
            NS  ns1.main.tld.
$ORIGIN main.tld.
00          A   x.x.x.x
            MX  10 00
            TXT "v=spf1 a mx -all"
            CAA 0 issue "letsencrypt.org"
$ORIGIN 00.main.tld.
*           A   x.x.x.x
_dmarc          TXT "v=DMARC1; p=none"
$ORIGIN main.tld.
01        MX  10 01
            TXT "v=spf1 a mx -all"
            CAA 128 issue "letsencrypt.org"
$ORIGIN 01.main.tld.
*           A   89.234.140.181
            AAAA    2a00:5881:4008:7500::42
_dmarc          TXT "v=DMARC1; p=none"

We need to handle these multiple $ORIGIN lines.