Don't update DOM when line didn't change

[jcubic]

I have an idea for a new feature for jQuery Terminal

It may improve performance if library don't force update DOM when line didn't changed.

this is the code to update the line with a function on every frame:

    const index = term.last_index();
    (function loop() {
        if (!stop) {
            const new_message = fn();
            if (new_message !== message) {
                message = new_message;
                // update only when value changes
                term.update(index, new_message);
            }
            requestAnimationFrame(loop);
        }
    })();

The code need to check if the value change, we can simplify the user code by do this in the library.

[jcubic]

This is already implemented.