- off pointercancel event

IE-11 supports css pointer-events incorrect:
if your draggable elem contains pseudoelements,
Sortable.js will solve that your draggable elem
are dropping to itself.
So Sortable.js will place your draggable elem to end of list.

This PR let to Sortable.js solve that IE11 doesnt support pointer-events

Currently in IE9 dragging an element does select the text because document.selection.empty() does fire to early. Adding the timeout fixes this problem.

Tweaked callbacks overwriting and preventing to trying of calling
strings

This event will fire when an element is chosen, and is particularly
useful for providing the user with a visual, auditory or tactile indication,
in case a delay was enabled.

And so on: #558, #547, #542, #537, #532, #516, #500, #489, #489, #447, #475, #459, ##422, #411, #356

when nesting Sortable's, we're not interested in this error:
"HierarchyRequestError: Failed to execute 'appendChild' on 'Node': The new child element contains the parent."

As done in the other place where `dataTransfer` is used.
This is to support fake html5 drag and drop events, where `dataTransfer` is not accessible. Use case: Selenium testing with ePages-de/chromedriver-html5-dragdrop

Fixes #488

#356 Fixing issue where dropping an item on the right end of a horizontally layed out drop zone does not add the item

Bump minor version number

All modern browsers seem to support `window.pageXOffset` and `window.pageYOffset`, which are aliases for `window.scrollX` and `window.scrollY`.

IE doesn't seem to have `window.scrollX` and `window.scrollY`.

fixes #302