Draggable: append divs to iframe parent for iframefix

This allows the blocking div to move with the iframe in
most situations, whereas appending to the body wouldn't.

Fixes #9671
Draggable: Ensure correct widget removes helper in connectToSortable
Draggable: Ensure css is always restored after connectToSortable drag

Fixes #9675
Draggable: Ensure sortable revert still works after draggable is removed

Fixes #9481
Draggable: Clarify comments and whitespace in connectToSortable
Draggable: Refresh sortables when draggable is added or removed

Since a sortable grows or shrinks when a draggable element is added
to it, refresh the cached positions of sortables whenever an element
is added or removed from the sortable.

Refs #9675
Draggable: Whitespace and naming cleanup of connectToSortable
Sortable: cancelHelperRemoval only considers helper, not placeholder

Refs #9675
Draggable: Add battery of tests to cover connectToSortable

Refs #9481
Refs #9675
Closes gh-1323
Widget: Ensure window and document are defined in _getCreateOptions()

Closes gh-1320
Menu: Ignore mouseenter events while typeahead is actice

Prevents focusing the wrong item when typeahead causes a scroll while the mouse
is over an item in the menu.

Fixes #10458
Tabs: Fix description in ajax demo

Closes jquery/jqueryui.com#90
Widget: modify this.window test to support IE8 window equality quirk

Comparing this.window with strict equality fails in IE8
Effects Tests: Fix and format scale visual test
Effects Tests: Add shake visual test

Closes gh-1328
Tests: Cleanup
CONTRIBUTING: Close parenthesis

Closes gh-1337
Effects tests: Add clip visual test

Closes gh-1338
Effects Demos: Fix typeErrors on puff and size demos
Menu: Adding a demo showing how to create category headers

Closes gh-1347