Fix a long standing bug on the 404 page.

The 404 page is only supposed to present a link to create a tiddler
or a links to possible other tiddlers you might be looking for if
in fact you are looking at a tiddler URI. Instead it was doing it
pretty much all the time. I think this was @jdlrobson , so pinging
him so he's aware.

Anyway, the change says to only present the tiddler info if:

* the path is only one segment long and is not 'bags' or 'recipes'
* the path is 4 segments long

src/errors/errorHandling.js

@@ -31,7 +31,13 @@ var errorhandler = {
 			if(path) {
 				var segments = path.split("/");
 				var tiddler = segments[segments.length - 1];
-				if(tiddler) { // currently only for for tiddler uris
+                                var bagsP = $.inArray('bags', segments);
+                                var recipesP = $.inArray('recipes', segments);
+                                var segmentsCount = segments.length;
+                                if ((segmentsCount == 1
+                                            && bagsP == -1
+                                            && recipesP == -1)
+                                        || segmentsCount == 4) {
 					errorhandler.suggestTiddlers(container, space, tiddler);
 				}
 			} else {