avoid hanging on HTTP GETting the apt package list

[djs55]

On my build machine several tedious seconds are wasted on every package build around here:

Ign file: ./ Translation-en                                                
Hit http://ppa.launchpad.net raring Release.gpg                                                
Hit http://ppa.launchpad.net raring Release    
Hit http://ppa.launchpad.net raring/main amd64 Packages
Ign http://ppa.launchpad.net raring/main Translation-en
Hit http://gb.archive.ubuntu.com raring Release.gpg
Hit http://gb.archive.ubuntu.com raring Release
75% [Waiting for headers] 

Nothing is ever actually fetched though.

[euanh]

Yup, I've just been playing with squid, apt-cacher-ng and a couple of others to try to speed up the package installation phase. Not quite got it working yet...