Set the default editor inside the chroot

Allows the chroot builder to set the default editor to be used in the
chroot.

Vim is used as the default choice.

Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Helga Velroyen <helgav@google.com>

devel/build_chroot

@@ -5,6 +5,7 @@
 : ${DIST_RELEASE=squeeze}
 : ${CONF_DIR:=/etc/schroot/chroot.d}
 : ${CHROOT_DIR:=/srv/chroot}
+: ${ALTERNATIVE_EDITOR:=/usr/bin/vim.basic}
 
 #Automatically generated variables
 CHROOTNAME=$DIST_RELEASE-$ARCH
@@ -150,6 +151,10 @@ in_chroot -- \
 in_chroot -- \
   cabal install --global shelltestrunner
 
+#Set default editor
+in_chroot -- \
+  update-alternatives --set editor $ALTERNATIVE_EDITOR
+
 rm -f $COMP_FILEPATH
 echo "Creating compressed schroot image..."
 cd $CHDIR