Avoid unnecessary scrolling at startup

The main fix is removing the fallback navigation to the first tiddler
in story.js. Also required is the fix to the startup behaviour of
zoomin.js.

Fixes #981

core/modules/startup/story.js

@@ -133,8 +133,6 @@ function openStartupTiddlers(options) {
 			target = target.substr(2,target.length - 4);
 		}
 		$tw.wiki.addToHistory(target);
-	} else if(storyList.length > 0) {
-		$tw.wiki.addToHistory(storyList[0]);
 	}
 }
 

core/modules/storyviews/zoomin.js

@@ -30,7 +30,7 @@ var ZoominListView = function(listWidget) {
 		if(!(domNode instanceof Element)) {
 			return;
 		}
-		if(targetTiddler !== itemWidget.parseTreeNode.itemTitle || (!targetTiddler && index)) {
+		if((targetTiddler && targetTiddler !== itemWidget.parseTreeNode.itemTitle) || (!targetTiddler && index)) {
 			domNode.style.display = "none";
 		} else {
 			self.currentTiddlerDomNode = domNode;