Might want to update /releases/ to be less proud of MD5

[Ben Harris <bjh21@cam.ac.uk>]

I was just looking at <http://www.debian.org/releases/> and noticed this 
text:

"Data integrity is granted by a digitally signed Release file. To ensure 
that all files in the release belong to it, MD5 checksums of all Packages 
files are copied into the Release file.

I think it might be worth updating this to say "SHA-256" in place of 
"MD5", since MD5 is looking a little weak these days.  Alternatively, 
since the precise algorithm is not really relevant (and not mentioned for 
the signature), maybe replacing "MD5 checksums" with "cryptographic 
hashes" would be better and more future-proof.

--
Ben Harris, University of Cambridge Information Services.  Tel: (01223) 334728