update

+deleted useless classes
+key board shortcuts

List of keyboard shortcuts:
In Main menu:
-new (ctrl + n)
-refresh (ctrl +F5)
-search (ctrl + f)
In record view/patient view
-next page (ctrl + right arrow key)
-previous page (ctrl + left arrow key)
-print (ctrl + p) [for record only]
-discard changes (ctrl + d)
-save (ctrl + s)
-edit (ctrl + e)
-back (ctrl + backspace)
-delete (ctrl + delete)