Some trackbacks timeout due to short timeout period

[gnaka08]

A trackback by WordPress to an external blog can timeout without any network congestion. WordPress 2.8.1 timeouts if it has not received any response from the receiving system for 4 seconds although some blog system can take more than 10 seconds to accept a trackback. If the trackback fails, WordPress keeps trying to resend the trackback every time the user posts a new entry, but it never succeeds and WordPress keeps resending for ever. It annoys the blog owner whose blog the WordPress is trying to send the trackback to.

I propose that function trackback in wp-includes/comment.php should be modified for the timeout period to be extended from 4 seconds (e.g. to 30 seconds).

This modification is different from one appeared in ticket #8665.

The timeout in MT4.261 seems to be 60 seconds by default (HTTPTimeout configuration variable). The documentation claims that it is 10 seconds somehow, but lib/MT/Core.pm reads as 60 seconds to me.

 http://www.movabletype.org/documentation/appendices/config-directives/httptimeout.html

Japanese-localized documentation tells that it has been changed to 60 seconds since version 3.3.

 http://www.movabletype.jp/documentation/appendices/config-directives/httptimeout.html

Punting due to lack of testing and community traction.