Remove openDatabase error when loading jIO.

Do not display error in browser not implementing WebSQL.
WebSQLStorage will raise an error is used in such browsers.

src/jio.js

 /*global window, RSVP, Blob, XMLHttpRequest, QueryFactory, Query, atob,
-  FileReader, ArrayBuffer, Uint8Array */
+  FileReader, ArrayBuffer, Uint8Array, navigator */
 (function (window, RSVP, Blob, QueryFactory, Query, atob,
-           FileReader, ArrayBuffer, Uint8Array) {
+           FileReader, ArrayBuffer, Uint8Array, navigator) {
   "use strict";
 
+  if (window.openDatabase === undefined) {
+    window.openDatabase = function () {
+      throw new Error('WebSQL is not supported by ' + navigator.userAgent);
+    };
+  }
+
   var util = {},
     jIO;
 
@@ -504,4 +510,4 @@
   window.jIO = jIO;
 
 }(window, RSVP, Blob, QueryFactory, Query, atob,
-  FileReader, ArrayBuffer, Uint8Array));
+  FileReader, ArrayBuffer, Uint8Array, navigator));

test/jio.storage/websqlstorage.tests.js

@@ -11,9 +11,17 @@
     equal = QUnit.equal,
     module = QUnit.module,
     big_string = "",
-    db = openDatabase('jio:qunit', '1.0', '', 2 * 1024 * 1024),
+    db,
     j;
 
+  try {
+    db = openDatabase('jio:qunit', '1.0', '', 2 * 1024 * 1024);
+  } catch (ignore) {
+  }
+  if (db === undefined) {
+    return;
+  }
+
   function getSpy() {
     return new RSVP.Promise(function (resolve, reject) {
       var spy;