Bug#874326: apt-get should provide a clear message if not root

[Jonny Grant <jg@jguk.org>]

Package: apt
Version: 1.2.24

Basically apt-get must run as root, so therefore the message should be 
appropriate. Can apt-get not provide a clearer message when that is the 
case?

Expected output
===============

$ apt-get update
Reading package lists... Done
E: Permission denied. apt-get must be run as root user
$


Current output
==============

$ apt-get update
Reading package lists... Done
W: chmod 0700 of directory /var/lib/apt/lists/partial failed - 
SetupAPTPartialDirectory (1: Operation not permitted)
E: Could not open lock file /var/lib/apt/lists/lock - open (13: 
Permission denied)
E: Unable to lock directory /var/lib/apt/lists/
W: Problem unlinking the file /var/cache/apt/pkgcache.bin - RemoveCaches 
(13: Permission denied)
W: Problem unlinking the file /var/cache/apt/srcpkgcache.bin - 
RemoveCaches (13: Permission denied)
$