Auto truncate status bar titles

[spencerwooo]

As you can see, sometimes the status bar text is too long when displaying web pages with long titles. Take powerline/powerline for example. An option to truncate the title automatically would be nice. 👍

[awave1]

should the title truncate only if it overlaps with left or right parts of the bar?

[tsujp]

Perhaps a setting such that when x% of the bar's horizontal width is taken up the title is truncated with ellipses .... Will need some constant width set for the ellipses since they will technically add length also.

I might take a shot at this later.

[koekeishiya]

Fixed on master, but couldn't be bothered with the additional complexity to add an ellipsis at the end.