Subject:  Added code for sending login and logout timings of user to the backend

Description:
1. onbackpressing menu page, it generates a popup which asks for logout to the user
   on selecting 'Yes' button, sends 'login time' which was stored in static varible during
   actual login and 'logout time' will be sent to a database.

2. so that when admin selects option to view other user's details
   he/she will able to see login and logout timings along with username.