Fixed loop terminating. Faster termination.

Replaced Scanner with a BufferedReader to read the input stream of System.in. Being synchronized, it makes termination of the line counter loop a lot quicker than with a System.in scanner (because main thread is not that busy). Handled NullPointerException for when line counter loop is terminated (leading the application to stop running). Fixed some tabbing. Known bugs: "Enter root directory: " is not displayed upon a non-early-terminated line count. It will still read input from System.in, but it is just not printed.