Time display

Display time in format hh:mm:ss instead of soconds like in toc.

Normally MATLAB itself supplies a set of buildin function tic and toc to read stopwatch timer. But toc returns time in seconds, and accumulate every time when user type 'toc' before another 'tic' is entered. sometimes it is hard to read a during time in seconds. So this function helps to convert seconds to normal digital watch format hh:mm:ss.