minor update on readme file
Removed from the repository all references of copyrighted materials borrowed from Vladyslav Volovyk, and added a notice in README.
added new div element for root of subtree, so it can be hovered
made span element for tab title highlighted when tab is activated
fixed close and doubleclick methods so they can reach the right window
added activate selector for hovering menu's close button and commented out hover on li element