Added password feature.

I am currently working on a project which requires a very simple interface for user login. And I really appreciate this tool. 

To fit my specific need, I added features for password input. It looks every old-fashioned and is pretty much the same style as terminal.  And I tried it with following code.

```javascript
var myTerminal = terminal();
			myTerminal.setBackgroundColor("#000000");
			myTerminal.setTextColor("#ffffff");
			myTerminal.setWidth("60%");
			myTerminal.setHeight("230px");
			myTerminal.blinkingCursor(false);
			$("body").append(myTerminal.html());
			myTerminal.password("What's your name?", function (userInput) {
			myTerminal.print("Welcome, " + userInput + "!");
			});
```

So, I thought you might want to know.