Infinite Redirect Loop: Lock file + temp dir permissions

Hello, I commented on this issue here: #310656: Some Imagecaches producing a loop redirect. But, I believe this is a separate issue from the memory limit problem.

The problem I had was the IIS user had permission to write to the temp directory but did not have permission to delete, so it would hang in a "already generating" state since it could create the lock but not delete it.

If the user has permission to write and delete everything is cool.
If the user DOES NOT have permission to write everything still works.
If the user has permission to write but no DOES NOT have permission to delete, it gets stuck.