Docs for result::collect and option::collect should use boxed pointers and `Vec`s

[nathantypanski]

They both follow basically the same format:

fn inc_conditionally(x: uint) -> Option<uint> {
    if x == uint::MAX { return None; }
    else { return Some(x+1u); }
}
let v = [1u, 2, 3];
let res = collect(v.iter().map(|&x| inc_conditionally(x)));
assert!(res == Some(~[2u, 3, 4]));

These should be updated to use box and Vec.

Edit:

• Updated title to reflect below comment. No box was necessary.

[huonw]

This should just be updated to use Vec, no Box. ~[] was a single type that was entirely replaced by Vec. (i.e it was not equivalent to ~T with T= [].)

[nathantypanski]

@huonw

:( right, there's no Box necessary anymore. Just Vec. I got it right in the code, but I wonder if I should reword the commit about it.

[nathantypanski]

Reworded and resubmitted as mentioned.