fix(client): Do not attempt to re-focus an element that has been blurred before the refocus occurs.

@vladikoff - wanna r?

Fixes Selenium/ChromeDriver where an attempt is made to autofocus an element
after ChromeDriver has already moved on to the next element.

The timing was:
1) A new view was rendered, an autofocus element found.
2) The autofocus element was focused, a timer set to check for focus 50ms later.
3) In that 50ms, ChromeDriver would fill out the field, and move on to the next field.
4) The timer expired, and the view tried to re-focus the autofocus element.
5) ChromeDriver failed the test.

fixes #1329 (on a mac)