Cursor animation is affected by update in interval

[jcubic]

Issue summary

If you have update every 500ms, it affect the cursor animation

Expected behavior

CSS animation is not affected by term::update()

Actual behavior

Every other blink it gives few frames without blinking

Steps to reproduce

1. Open Timer demo https://codepen.io/jcubic/pen/PogVJmB?editors=0010
2. focus and wait few seconds

Browser and OS

N/A

Additional notes

It may be caused by a call to reset the animation in CMD.

[jcubic]

The problem is that term::flush() call this code at the end:

if (enabled && !is_mobile) {
    // Firefox won't reflow the cursor automatically, so
    // hide it briefly then reshow it
    cmd_cursor.hide();
    self.oneTime(1, 'flush', function() {
        cmd_cursor.show();
    });
}

So it may be not possible to fix.