cursivebufferedbackend

The buffering backend for any Cursive backend. Mainly it is created to address a flickering issue with Termion backend.

Inspired by the comment on the similar issue on Termion itself.

Usage

```rust let backendinit = || -> std::io::Result> { let backend = cursive::backends::termion::Backend::init()?; let bufferedbackend = cursivebufferedbackend::BufferedBackend::new(backend); Ok(Box::new(buffered_backend)) };

let mut app = Cursive::new(); app.tryrunwith(backend_init).ok()?; ```