Switch to bz2 from gzip.

bz2 indicies should be available on all mirrors, while being considerably
smaller (and therefor faster to download).

get-upstream-dists

@@ -26,7 +26,7 @@ set -ex
 
 # For each of the dists we target, download the packages files.
 for dist in '' -security $EXTRAS; do
-	wget -q -c -m -np -nH --cut-dirs=3 -A "Packages.gz" -A "Sources.gz" -P$WORKINGDIR/dists-download \
+	wget -q -c -m -np -nH --cut-dirs=3 -A "Packages.bz2" -A "Sources.bz2" -P$WORKINGDIR/dists-download \
 		$MIRROR/dists/$MIRRORDIST$dist/
 done
 
@@ -34,8 +34,8 @@ done
 rsync -a $WORKINGDIR/dists-download/* $MIRRORLOCAL/dists/
 
 # Extract the lists so awk can handle them
-find $MIRRORLOCAL/dists/ -name Packages.gz -exec gunzip -f {} \;
-find $MIRRORLOCAL/dists/ -name Sources.gz -exec gunzip -f {} \;
+find $MIRRORLOCAL/dists/ -name Packages.bz2 -exec bunzip2 -f {} \;
+find $MIRRORLOCAL/dists/ -name Sources.bz2 -exec bunzip2 -f {} \;
 
 # Tidy up.
 rm -rf $WORKINGDIR/dists-download