?cpage=N URLs do not have canonical redirection

[markjaquith]

?cpage=N URLs aren't redirected to their pretty URL counterparts. They should be.

[cklosows]

Tested on trunk build (3.4-beta4-20838) and this appears to be working.

localhost/wordpress/hello-world?cpage=2 -> localhost/wordpress/hello-world/comment-page-2/ (via a 301 redirect)

[SergeyBiryukov]

Seems to work for me as well.

Introduced in #7942:
​http://core.trac.wordpress.org/browser/tags/3.3.2/wp-includes/canonical.php#L256

[wonderboymusic]

In 26091:

Set the page_comments option to true in Tests_Canonical to properly check canonical redirection for paged comments. By doing so, one assertion tied to #20388 no longer needs to be.

See #20388, 25913.

[wonderboymusic]

The redirection works when the page_comments option is true. However, the other 2 assertions that check for redirection of out of range comment pages still fail.