Anonymous upload Feature as requested in #740

Hi,

this is a new patch for the anonymous upload feature requested in Issue #740 for review. The patch has been inspreided by sojer's attempt to deliver this patch #2780. This patch is a complete rewrite from scratch implementing CRUDS and hopefully eliminating the security issues mentioned in sojers pull request. Please take a careful look at my changes to the upload.php file as I'm not entirely sure about security in there. The line in question is well documented.

Special thanks to sojer who's code gave me an idea about how to basically go around this problem, and the IRC dev channel (AnybodyElse, bartv, Raydiation and anyone else who gave me advice on this).

cu
Roman