ISIS UX Warning message when about to leave edit

#### Lets be more Informative

When editing an article, menu, category (anything singular), and press the back button the refresh or the close button on the browser, user most probably will loose any data without warning. This PR throws a standard browser window with custom message to inform him/her. Of course we are not forcing anything he/she can go ahead and close the window, but we did informed them 
@dgt41 please add a space between the `:`and the `?>` Thanks