Dirty hack for MW-1.19.1 (fix upload images on some hosters)

Hi, mr. All!

When i installed MW-1.19.1 on my hosting i got error messages like

'rename() [function.rename
<http://fwiki.whitefossa.ru/index.php/function.rename>]: SAFE MODE
Restriction in effect. The script whose uid is 55398 is not allowed to
access /var/tmp owned by uid 0 in
*/home/u48601/whitefossaru/fwiki/includes/upload/UploadStash.php* on
line *173*'

when trying to upload any image.

Safe mode was turned OFF, but this error didn't disappear.

Investigations, made by me and Sir. Sheti <sheti <at> furtails.ru> revealed, that my hoster is completely
moron. He uses one tempdir /var/tmp for all users of server, and, this directory belongs to root:root.
Because it any modification in this directory fails. And, hoster don't allow to change this directory.

So, here is dirty workaround by Sheti:

1) Create temp directory in filesystem, accessible by you, than chmod -R 777 it

2) Locate file <mediawiki_dir>/includes/GlobalFunctions.php

3) Find function named 'wfTempDir()' and comment it (this function determines temp directory):

  //Hoster are idiot, we must make temp yourself
  /*
function wfTempDir() {