make setup error a little more verbose

if a subdir is not setup properly, then init_paths() in inc/init.php will use
the pretty name ("datadir" instead of "pages"; "olddir" instead of "attic").
attached patch simply includes the actual directory name in the output so
people dont have to look it up in the source
code.

darcs-hash:20061211194244-5224c-2d22eeb08d770108d1d993783e95d11bef0e8855.gz

inc/init.php

@@ -140,7 +140,7 @@ function init_paths(){
   foreach($paths as $c => $p){
     if(empty($conf[$c]))  $conf[$c] = $conf['savedir'].'/'.$p;
     $conf[$c]             = init_path($conf[$c]);
-    if(empty($conf[$c]))  nice_die("The $c does not exist, isn't accessable or writable.
+    if(empty($conf[$c]))  nice_die("The $c ('$p') does not exist, isn't accessable or writable.
                                You should check your config and permission settings.
                                Or maybe you want to <a href=\"install.php\">run the
                                installer</a>?");