ipv4 classification issues

Some tools accept 32b integer as valid ipv4 (e.g. browser) but faup doesn't classify them as ipv4

```
faup -f url_type 127.0.0.255
ipv4
faup -f url_type 2130706433
no_tld
faup -f url_type http://2130706433
no_tld
```
