Refactoring center panel away. Moving tutorial to a route. Fixing a

bunch of bugs.

webapp/stores/post_store.jsx

@@ -406,7 +406,7 @@ class PostStoreClass extends EventEmitter {
         let posts;
         let pendingPosts;
         for (const k in this.postsInfo) {
-            if (this.postsInfo[k].postList.posts.hasOwnProperty(this.selectedPostId)) {
+            if (this.postsInfo[k].postList && this.postsInfo[k].postList.posts.hasOwnProperty(this.selectedPostId)) {
                 posts = this.postsInfo[k].postList.posts;
                 if (this.postsInfo[k].pendingPosts != null) {
                     pendingPosts = this.postsInfo[k].pendingPosts.posts;

webapp/stores/search_store.jsx

@@ -16,7 +16,7 @@ class SearchStoreClass extends EventEmitter {
     constructor() {
         super();
 
-        this.searchResults = {};
+        this.searchResults = null;
         this.isMentionSearch = false;
         this.searchTerm = '';
     }