maint: whitespace cleanup

* .dir-locals.el (html-mode): Let emacs help out.
* cfg.mk (sc_TAB_in_indentation): Check more files.
* docs/internals/command.html.in: Fix offenders.
* docs/formatdomain.html.in: Likewise.
* docs/internals.html.in: Likewise.
Reported by Jiri Denemark.

.dir-locals.el

@@ -5,4 +5,7 @@
             (c-indent-level . 4)
             (c-basic-offset . 4)
             ))
+ (html-mode . (
+	       (indent-tabs-mode . nil)
+	       ))
  )