Complete :sanitize and private mode overhaul.

--HG--
rename : common/content/sanitizer.js => common/modules/sanitizer.jsm

common/content/bookmarks.js

@@ -280,6 +280,7 @@ const Bookmarks = Module("bookmarks", {
             names: ["-tags", "-T"],
             description: "A comma-separated list of tags",
             completer: function tags(context, args) {
+                // TODO: Move the bulk of this to parseArgs.
                 let filter = context.filter;
                 let have = filter.split(",");