Rename the settings whose names do not say what they control (closes #234)

Applies the setting renames of the naming audit under the SWW_WAF_ and
SWW_RPROXY_ prefixes, with sneak's names for the IP reputation cache
time and the two time limits, which now take milliseconds. The rproxy
log field default_disposition becomes waf_backend_no_answer, and
config.Config and config.FromEnvironment become config.WAF and
config.WAFFromEnvironment. Go fields, test names and prose follow. No
aliases; nothing reads the old names.

Model: opus-5-5

internal/sww/sww_internal_test.go

@@ -66,7 +66,7 @@ func stopHeldSender(t *testing.T, release time.Duration) time.Duration {
 			Scheme: remotelog.SchemeTCP,
 			Host:   "127.0.0.1:65536",
 		},
-		Buffer: 1,
+		BufferLines: 1,
 	})
 
 	stopSending := startSending(t.Context(), sender,