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/reputation/dnsbl_test.go

@@ -40,8 +40,9 @@ const (
 	// zone and otherZone are the DNSBL zones the tests name.
 	zone      = "dnsbl.example"
 	otherZone = "other.example"
-	// cacheTTL is the tests' SWW_WAF_REPUTATION_CACHE_TTL, and timeout their
-	// SWW_WAF_REPUTATION_TIMEOUT: a second, the least time /etc/resolv.conf
+	// cacheTTL is the tests' SWW_WAF_IP_REPUTATION_CACHE_TTL, and timeout
+	// their SWW_WAF_DNSBL_ABUSEIPDB_TIMEOUT_MS: a second, the least time
+	// /etc/resolv.conf
 	// can have Go's resolver wait for one server, so that it is the
 	// DNSBL's own timeout that ends a query, whatever that file says.
 	cacheTTL = 24 * time.Hour