Don't focus note editor when pressing Shift-Tab on note in middle pane

Reverts redundant code from 7e39e46 (zotero#1136) and fixes the much earlier
9d7cc84 (zotero#151)

chrome/content/zotero/xpcom/itemTreeView.js

@@ -129,19 +129,6 @@ Zotero.ItemTreeView.prototype.setTree = Zotero.Promise.coroutine(function* (tree
 				return;
 			}
 
-			// Focus note editor when Tab is pressed on a selected note
-			if (event.keyCode == event.DOM_VK_TAB) {
-				let items = this.getSelectedItems();
-				if (items.length == 1 && items[0].isNote()) {
-					let noteEditor = this._ownerDocument.getElementById('zotero-note-editor');
-					if (noteEditor) {
-						noteEditor.focus();
-						event.preventDefault();
-					}
-				}
-				return;
-			}
-
 			// Handle arrow keys specially on multiple selection, since
 			// otherwise the tree just applies it to the last-selected row
 			if (event.keyCode == 39 || event.keyCode == 37) {

chrome/content/zotero/zoteroPane.js

@@ -593,14 +593,13 @@ var ZoteroPane = new function()
 			}
 		}
 		else if (from == 'zotero-items-tree') {
-			// Focus TinyMCE explicitly on tab key, since the normal focusing
-			// doesn't work right
-			if (!event.shiftKey && event.keyCode == String.fromCharCode(event.which)) {
+			// Focus TinyMCE explicitly on tab key, since the normal focusing doesn't work right
+			if (!event.shiftKey && event.keyCode == event.DOM_VK_TAB) {
 				var deck = document.getElementById('zotero-item-pane-content');
 				if (deck.selectedPanel.id == 'zotero-view-note') {
-					setTimeout(function () {
-						document.getElementById('zotero-note-editor').focus();
-					}, 0);
+					document.getElementById('zotero-note-editor').focus();
+					event.preventDefault();
+					return;
 				}
 			}
 			else if ((event.keyCode == event.DOM_VK_BACK_SPACE && Zotero.isMac) ||