curl multi backport to PHP4

I needed the curl multi stuff for something, so I trivially backported it to PHP4's ext/curl. There is nothing really PHP5-specific in it and it is basically just a standalone extension keeping track with the 3rd-party library it is wrapping. Ilia, as RM of the 4.3 tree, do you see any reason not to commit this to ext/curl on the PHP_4_3 branch after 4.3.9 is out the door? -Rasmus