timrwood/moment — pull request #390 by icambron (2012-08-08 06:50:57+00:00)
Title: optional immutability

I wrote this as an experiment, and figured I'd submit it as a pull request. I created a global flag that makes moment objects immutable, forcing each of the manipulation functions clone the moment object before
doing their work. So:

```js
mutable = moment()
mutable.add("s", 3) == mutable // => true
moment.immutable = true
immutable = moment()
immutable.add("s", 3) == immutable // => false
```

I do like immutability a lot, but I could see where this might not be ideal maintainability-wise, so NBD if you don't want it. Let me know what you guys think.