Re: Cube extension kNN support

Hi, thanks for the review.

> 1) (nitpicking) There seem to be some minor whitespace issues, i.e.
> trailing spaces, empty lines being added/removed, etc.

Fixed, I think

> 2) one of the regression tests started to fail
>
> SELECT '-1e-700'::cube AS cube;
>
> This used to return (0) but now I get (-0).

Actually that problem emerged because of the first problem. I had extra whitespace in sql file and removed that whitespace from one of the answers file (cube_1.sql), so diff with both cube.sql and cube_1.sql was one line length and you saw diff with cube.sql.
In all systems that available to me (osx/linux/freebsd) I saw that right answers file is cube_1.sql. But in other OS’es you can get +/- 0 or e27/e027. I edited that answers files manually, so there probably can be some other typos.

> 3) I wonder why the docs were changed like this:
>
> <para>
> - It does not matter which order the opposite corners of a cube are
> - entered in. The <type>cube</> functions
> - automatically swap values if needed to create a uniform
> - <quote>lower left &mdash; upper right</> internal representation.
> + When corners coincide cube stores only one corner along with a
> special flag in order to reduce size wasted.
> </para>
>
> Was the old behavior removed? I don't think so - it seems to behave
> as before, so why to remove this information? Maybe it's not useful?
> But then why add the bit about optimizing storage of points?

I’ve edited it because the statement was mislead (or at least ambiguous) — cube_in function doesn’t swap coordinates.
Simple way to see it:
> select '(1,3),(3,1)'::cube;
cube
---------------
(1, 3),(3, 1)

But LowerLeft-UpperRight representation should be (1,1),(3,3)

Updated patch attached.