Restructuring of plugin to use prototype (Suggestion of Edygar).
New options for the selectors.
Merge branch 'master' of https://github.com/andersonlevita/eNestedSortable
Ajust README.md
Version change.
Fix remove style of list item on drag start.
Fix drop bug.
Fix get drag element.
Changing prototype attribution to extend instead overwriting

Now, `Plugin.prototype` is extended instead of overwritten and
all methods are accessible through the following:
* `$.fn.eNestedSortable('method', args...)`
Quickfix to CSS on example

Now, the list numbers are shown inside the element
so a small glitch while dropping over a number is fixed