Bug#41231: apt: apt-cdrom should work for source CDs

[tom@lpsg.demon.co.uk]

Package: apt
Version: 0.3.11
Severity: normal

I have several source CDs. Now that APT can handle source code URIs,
apt-cdrom should also be upgraded to handle source CDROMs (at least
as generated by the slink debian-cd package).

-- System Information
Debian Release: 2.1
Kernel Version: Linux lpsg 2.2.9 #4 Fri May 21 13:11:48 BST 1999 i586 unknown

Versions of the packages apt depends on:
ii  libc6           2.1.1-0.2      GNU C Library: shared libraries
ii  libstdc++2.9-gl 2.91.63-1.1    The GNU stdc++ library (egcs version)