[plug] setuid etc

[Craig Ringer]

>>The EUID set but the api doesn't actually set the UID, so I wrote a little
>>program to make sure what was launched had EUID and UID set correctly.
>>
>>I just wondered whether there was a unix app that did this already.

> So, with sudo:
> 
>   $ sudo su root ./uids
>   uid=0
>   euid=0
>   $

However, this means that you have to set sudo to allow users to run 
"su", kind of defeating the use of sudo for /limited/ root access.