Cases that now send errors:
* Malformed IP address (SOCKS5_GENERAL_ERROR)
* CONNECT/RESOLVE request with IP, when SafeSocks is set
(SOCKS5_NOT_ALLOWED)
* RESOLVE_PTR request with FQDN (SOCKS5_ADDRESS_TYPE_NOT_SUPPORTED)
* Malformed FQDN (SOCKS5_GENERAL_ERROR)
* Unknown address type (SOCKS5_ADDRESS_TYPE_NOT_SUPPORTED)
Fixes bug 13314.