[p4] Trigger to restrict users to delete any file

[Robert Cowham]

>   I want to keep a close watch to the perforce developers / 
> users regarding file deletions. Users are deleting files 
> using "Open for Delete"  - > "Submit" and then they are not 
> running "pr obliterate" to remove the file permanently. This 
> is causing a big problem and we the depot now containing lost 
> of unused files (and they will not use those files in future also). 

Why is it a big problem?