Lower limits for listed AS numbers and countries (closes #21)

SWWAF_ASN_LIMIT_PERCENT and SWWAF_COUNTRY_LIMIT_PERCENT give the clients
of the AS numbers and countries they list that percentage of every rate
and byte limit, rounded down; SWWAF_ASN_BYTES_PERCENT and
SWWAF_COUNTRY_BYTES_PERCENT take its place for the byte limits of those
they list; SWWAF_UNKNOWN_LIMIT_PERCENT (100) covers clients without a
country. The lowest applies. While one lowers a limit, a request waits
for its client's lookup, and SWWAF_LOOKUP_SOURCE=off stops the start. Log
lines give limit_percent and bytes_percent with their settings; ban
notes, and so alerts, give the broken limit's.

Judgement call: a client without a country is unknown, whatever its AS number.
Judgement call: bytes_percent and its setting are log fields SPEC does not name.
Rule suppressed: funlen on FromEnvironment, one line per setting.

Model: opus-5-5

internal/ratelimit/snapshot_test.go

@@ -16,7 +16,7 @@ func TestSnapshotListsTheClientsByAddress(t *testing.T) {
 
 	limiter := ratelimit.New(ratelimit.Limits{})
 	for _, i := range []int{2, 3, 0, 1} {
-		limiter.Count(netip.MustParsePrefix(want[i]), midnight())
+		limiter.Count(netip.MustParsePrefix(want[i]), midnight(), whole)
 	}
 
 	snapshot := limiter.Snapshot()
@@ -63,8 +63,8 @@ func TestLoadEmptiesBucketsWhoseTimeHasPassed(t *testing.T) {
 	start := midnight()
 
 	limiter := ratelimit.New(ratelimit.Limits{})
-	limiter.Count(client, start)
-	limiter.CountBytes(client, start, 5)
+	limiter.Count(client, start, whole)
+	limiter.CountBytes(client, start, 5, whole)
 	limiter.AddToHistory(client, start, ratelimit.Request{Forwarded: true})
 
 	loaded := func(now time.Time) ratelimit.Client {