Repair cursor (closes DevExpress#1156) (DevExpress#1160)

* Revert overflow:hidden for ShadowUI root (closes DevExpress#1156)

* Fix cursor

package.json

@@ -2,7 +2,7 @@
   "name": "testcafe",
   "description": "Automated browser testing for the modern web development stack.",
   "license": "MIT",
-  "version": "0.12.0",
+  "version": "0.12.1",
   "author": {
     "name": "Developer Express Inc.",
     "url": "https://www.devexpress.com/"

src/client/ui/cursor/index.js

@@ -10,7 +10,6 @@ var messageSandbox = hammerhead.eventSandbox.message;
 
 var styleUtils    = testCafeCore.styleUtils;
 var positionUtils = testCafeCore.positionUtils;
-var eventUtils    = testCafeCore.eventUtils;
 
 const CURSOR_CLASS       = 'cursor';
 const TOUCH_CLASS        = 'touch';
@@ -71,8 +70,6 @@ var CursorUI = {
         }
 
         shadowUI.getRoot().appendChild(this.cursorElement);
-
-        eventUtils.bind(window, 'scroll', () => this.move(this.x, this.y));
     },
 
     isVisible () {
@@ -101,8 +98,8 @@ var CursorUI = {
             this._createElement();
 
         styleUtils.set(this.cursorElement, {
-            left: this.x + styleUtils.getScrollLeft(document) - this.pointerOffsetX + 'px',
-            top:  this.y + styleUtils.getScrollTop(document) - this.pointerOffsetY + 'px'
+            left: this.x - this.pointerOffsetX + 'px',
+            top:  this.y - this.pointerOffsetY + 'px'
         });
 
         return Promise.resolve();

src/client/ui/styles.less

@@ -16,7 +16,7 @@
     left: 0px;
     top: 0px;
     margin: 0 !important;
-    overflow: hidden;
+    overflow: visible;
 
     .layout-default();
 
@@ -188,7 +188,7 @@
     .cursor {
         .sprite-icon;
 
-        position: absolute;
+        .position-fixed();
         left: 0;
         top: 0;
         width: 35px;