rc-httpd/handlers/dir-index: plan 9 files may be chmod +a:

The mode printed under the -l option contains 11 characters,
          interpreted as follows: the first character is

          d    if the entry is a directory;

          a    if the entry is an append-only file;

          -    if the entry is a plain file.

Therefore, handle them in automatically generated directory listings.

rc/bin/rc-httpd/handlers/dir-index

@@ -82,7 +82,7 @@ function hrsize(size){
 	if(size > 1024) return sprintf("%.1fKB", size/1024)
 	return sprintf("%iB", size)
 }
-/^-/ {
+/^(-|a)/ {
 	print "<tr>"
 	print "<td class=\"size\">"hrsize($6)"</td>"
 	print "<td class=\"month\">"$7"</td>"