* Add a demo for checking password strength [example/readline-pass-strength](https://git.internal/re/readline/blob/master/example/readline-pass-strength/readline-pass-strength.go), , written by [@sahib](https://github.com/sahib)
* Add a demo for multiline [example/readline-multiline](https://git.internal/re/readline/blob/master/example/readline-multiline/readline-multiline.go) which can submit one SQL by multiple lines.
* Add a new simple apis for single instance, check by [here](https://git.internal/re/readline/blob/master/std.go). It need to save history manually if using this api.
* Only enter raw mode as needed (calling `Readline()`), program will receive signal(e.g. Ctrl+C) if not interact with `readline`.
* Bugs fixed for `PrefixCompleter`
* Press `Ctrl+D` in empty line will cause `io.EOF` in error, Press `Ctrl+C` in anytime will cause `ErrInterrupt` instead of `io.EOF`, this will privodes a shell-like user experience.