Issue with tab character in SelectView item

This is a bug report

# Problem description

When adding an item containing a tab character in a SelectView the text is truncated.

Some code to reproduce the issue:
```
extern crate native_tls;

use cursive::traits::*;
use cursive::views::{Dialog, SelectView};
use cursive::Cursive;

fn main() {
let mut select = SelectView::new();

select.add_item("there is a \ttab", 1);
select.add_item("there is no tab", 2);

let mut siv = Cursive::default();

siv.add_layer(
Dialog::around(select.fixed_size((20, 10)))
);

siv.run();
}
```

Here is the output I get:

# Environment

* Operating system: Ubuntu 19.04
* Backend used: ncurses 6.1
* Current locale: en_US.UTF-8
* Cursive version: 0.12.0