Print total working time when user interrupts program

At least on my system, these changes work to:

- Print the total working time if the user presses CTRL-C during a break.
- Print the total working time, minus remaining time in work session, if the user presses CTRL-C during a work session.

Had to set total working time variable before the `vsleep()` function call and also set a new variable to determine whether the user is in a break in order for this to work.