Display progress, pause or stop a time-consuming loop

This class creates a small pause/stop window, that allows you to either abort a running loop or pause the execution and create breakpoints or change/correct mistakes in the code (this works for files that are not in the stack from where stop.requested is called).

It can be used in different ways:
- Control the loop execution:
while ~stop.requested
%do your heavy calculations here
end
stop.close;

- abort execution in the middle
for i = 1:100
%do your heavy calculations here
if stop.requested
stop.close;
error('Stop requested')
end
end

- inform the current progress
iter = 1;
maxIter = 1000;

while iter<maxIter || stop.requested
%do your heavy calculations here
progress = iter/maxIter;
stop.setStatus('Running...',progress);
end
stop.close;

In loops with many iterations, you can also avoid updating the screen too often (and reduce the impact of calling stop.request), by calling: stop.requested(num); where num is the interval on which the gui will be refreshed to check for user interaction.

And to enable the easter egg (xkcd.com/1017/), use:
stop.setStatus('xkcd', progress);