Added Single event template and some functionality
-Added show action on EventController (link to show.gsp)
-Added show.gsp (The singleEvent page)
-Made the content of show.gsp's sidebars dynamic
-When on Single event, clicking the calendar redirects you to 
 the events page and the events after that date are displayed.
-When on Single event, clicking the category buttons redirects you to 
 the events page and the events of the selected category are displayed.