refactor(ngRepeat): simplify previousNode boundary calculation

the previousNode was almost always correct except when we added a new block in which case incorrectly
assigned the cloned collection to the variable instead of the end comment node.

Author: IgorMinar

src/ng/directive/ngRepeat.js

@@ -387,7 +387,6 @@ var ngRepeatDirective = ['$parse', '$animate', function($parse, $animate) {
             key = (collection === collectionKeys) ? index : collectionKeys[index];
             value = collection[key];
             block = nextBlockOrder[index];
-            if (nextBlockOrder[index - 1]) previousNode = getBlockEnd(nextBlockOrder[index - 1]);
 
             if (block.scope) {
               // if we have already seen this object, then we need to reuse the
@@ -411,9 +410,10 @@ var ngRepeatDirective = ['$parse', '$animate', function($parse, $animate) {
               $transclude(function ngRepeatTransclude(clone, scope) {
                 block.scope = scope;
                 // http://jsperf.com/clone-vs-createcomment
-                clone[clone.length++] = ngRepeatEndComment.cloneNode();
+                var endNode = ngRepeatEndComment.cloneNode();
+                clone[clone.length++] = endNode;
                 $animate.enter(clone, null, jqLite(previousNode));
-                previousNode = clone;
+                previousNode = endNode;
                 // Note: We only need the first/last node of the cloned nodes.
                 // However, we need to keep the reference to the jqlite wrapper as it might be changed later
                 // by a directive with templateUrl when its template arrives.