Use gzip compression for ubuntu-touch tarballs.

debian/changelog

@@ -1,6 +1,7 @@
 livecd-rootfs (2.128) UNRELEASED; urgency=low
 
   * Don't include lupin-casper in ubuntu-touch images.
+  * Use gzip compression for ubuntu-touch tarballs.
 
  -- Colin Watson <cjwatson@ubuntu.com>  Fri, 03 May 2013 08:45:11 -0700
 

live-build/auto/config

@@ -273,6 +273,7 @@ case $PROJECT in
 		export LB_BOOTSTRAP_INCLUDE='apt-transport-https gnupg'
 		OPTS="${OPTS:+$OPTS }--apt-recommends false"
 		OPTS="${OPTS:+$OPTS }--binary-filesystem ext4"
+		OPTS="${OPTS:+$OPTS }--compression gzip"
 		OPTS="${OPTS:+$OPTS }--swap-file-path SWAP.swap"
 		OPTS="${OPTS:+$OPTS }--swap-file-size 100"
 		OPTS="${OPTS:+$OPTS }--system normal"