Exposing internal functions of the dragDrop object - 'dragEnter', 'dragOver', 'drop' - to the $mouseHandler object.

I am developing an application in which the user drags a list-item from an outline to a document - upon which inserts all relevant information to that outline list item into the document.
Therefore, I need to change the default behavior of the ondrop listener for the Ace-powered document. My patch exposes the default methods for "dragEnter", "dragOver", and "drop", so that a developer can easily overwrite the default methods.
With this patch, the methods are accessible in both the **editor.$mouseHandler** object, and also in the **editor.$mouseHandler.dragDrop** object.
I will send my Contributors License Agreement as soon as I can.