AS number and country looked up for every client (closes #95)

GeoJS's geo.json is asked about every new visitor unless
SWWAF_LOOKUP_SOURCE is off. A request waits for its client's first
answer only while a country list or SWWAF_ADD_LOOKUP_HEADERS needs it;
otherwise the answer reaches the client's history and ban notes when it
comes. The AS number and name go beside the country in the request log,
history, ban notes, alerts and lookups.json, with metrics by AS number;
64512 counts as unknown. A client's own X-Client-ASN and
X-Client-Country never reach the app, whatever the setting says, and
make example-app sends no address to GeoJS.

Judgement call: AS numbers are written AS64496, as SPEC's settings write them.
Judgement call: SWWAF_LOOKUP_TIMEOUT is added, default 1s, and cannot be off.

Model: opus-5-5

internal/requestlog/requestlog.go

@@ -80,11 +80,14 @@ type Line struct {
 	// Request detail. RequestID is the X-Request-ID a trusted proxy sent,
 	// or a new one, and is sent on to the app. ForwardedFor is the
 	// X-Forwarded-For header as received. ClientGroup is the netblock the
-	// client is counted as.
+	// client is counted as. ASN, ASName and Country are the client's AS
+	// number, AS name and country, as looked up.
 	RequestID    string `json:"request_id"`
 	PeerIP       string `json:"peer_ip"`
 	ForwardedFor string `json:"forwarded_for,omitempty"`
 	ClientGroup  string `json:"client_group"`
+	ASN          string `json:"asn"`
+	ASName       string `json:"as_name"`
 	Country      string `json:"country"`
 	ContentType  string `json:"content_type,omitempty"`
 	// ContentLength is the length of its body the request announced.