X redis: v↑ (2.8.23)

- update Redis software to latest upstream in 2.8.* series (which now
  supports IPv6 out of the box);

- update Redis instance template to the one from 2.8.23 and re-merge our
  templating changes to it (file/dir locations, port and binding, master
  password).

  The whole diff to pristine 2.8.23 redis conf is now this:

  diff --git a/.../redis-2.8.23/redis.conf b/slapos/recipe/redis/template/redis.conf.in
  index 870959f..2895539 100644
  --- a/.../redis-2.8.23/redis.conf
  +++ b/slapos/recipe/redis/template/redis.conf.in
  @@ -46 +46 @@ daemonize no
  -pidfile /var/run/redis.pid
  +pidfile %(pid_file)s
  @@ -50 +50 @@ pidfile /var/run/redis.pid
  -port 6379
  +port %(port)s
  @@ -69,0 +70 @@ tcp-backlog 511
  +bind %(ipv6)s
  @@ -108 +109 @@ loglevel notice
  -logfile ""
  +logfile %(log_file)s
  @@ -174 +175 @@ rdbcompression yes
  -# hit to pay (around 10%) when saving and loading RDB files, so you can disable it
  +# hit to pay (around 10%%) when saving and loading RDB files, so you can disable it
  @@ -192 +193 @@ dbfilename dump.rdb
  -dir ./
  +dir %(server_dir)s
  @@ -217 +218 @@ dir ./
  -# masterauth <master-password>
  +%(master_passwd)s

XXX tests failure https://github.com/antirez/redis/issues/2715

XXX 2.8 because GitLab uses this series

/cc @alain.takoudjou

component/redis/buildout.cfg

@@ -6,9 +6,12 @@ parts =
 extends = ../tcl/buildout.cfg
 
 [redis]
+<= redis28
+
+[redis28]
 recipe = hexagonit.recipe.cmmi
-url = https://github.com/geoffgarside/redis/archive/ipv6.tar.gz
-md5sum = 0eb594bd4e8ee746a0e2ef67b28cb5d8
+url = http://download.redis.io/releases/redis-2.8.23.tar.gz
+md5sum = ac7f43f845d0eedb8ae3e5e217b34c61
 configure-command = true
 prefix = 
 make-options =