Added `all` and `any` builtins

**Disclaimer:** This is my first commit! I may have screwed it up somehow. In particular, I'm not feeling confident about the examples' output syntax.

Just some functional-ish gimmicks, inspired by Python's builtins of the same name.

I was unsure on whether or not convenience aliases like `any_by` or `all_by` would be of interest, so I left them out. Those would be defined like this:

```
def any_by(f): map(f) | any;
def all_by(f): map(f) | any;
```