prevent infinite recursion from tabpreview in navigate

package.json

@@ -92,7 +92,7 @@
         "c9.ide.immediate": "#6845a93705",
         "c9.ide.installer": "#7dae8e752a",
         "c9.ide.mount": "#896ebf836e",
-        "c9.ide.navigate": "#7c58c7f3d7",
+        "c9.ide.navigate": "#055a1f1a80",
         "c9.ide.newresource": "#f1f0624768",
         "c9.ide.openfiles": "#28a4f5af16",
         "c9.ide.preview": "#0bd8dd6e8c",

plugins/c9.ide.editors/tabmanager.js

@@ -35,7 +35,7 @@ define(function(require, module, exports) {
         var loadFilesAtInit = options.loadFilesAtInit;
         
         var PREFIX = "/////";
-        var XPREVIEW = /(tar\.gz|tar|tgz|zip)$/;
+        var XPREVIEW = /\.(gz|tar|tgz|zip|rar|jar|exe|pyc|pdf)$/;
         
         var unfocussed = true;
         var showTabs = true;