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/coreruleset/mediawiki.conf

@@ -5,7 +5,7 @@
 # request, before the rules it switches off, so this file is loaded before the
 # Core Rule Set's rules. Each comment names a request a rule refused. An
 # exclusion on a field of a body applies only when the query has no parameter of
-# that name, so it matters only while SWW_WAF_CORE_RULE_SET_BODY_LIMIT is set.
+# that name, so it matters only while SWW_WAF_CORE_RULE_SET_BODY_INSPECTION_SIZE is set.
 # MediaWiki's paths are matched at the site root and under /w/.
 #
 # WordPress serves /index.php too. So /index.php counts as MediaWiki's only