Update redis to 2.8.17.

--[ Redis 2.8.17 ] Release date: 19 Sep 2014

# UPGRADE URGENCY: HIGH for Redis Sentinel.
                   LOW for Redis Server (unmodified compared to 2.8.16).

* [FIX] Resolved a memory leak in the hiredis library causing a memory leak
        in Redis Sentinel when a monitored instance or another Sentinel is
        unavailable. Every reconnection attempt will leak a small amount of
        memory, but in the long run the process can reach a considerable size.

--[ Redis 2.8.16 ] Release date: 16 Sep 2014

# UPGRADE URGENCY: HIGH for Redis if you are using 2.8.15 + AOF.
                   LOW for Sentinel.

* [FIX] The ability to load truncated AOF files introduced with Redis 2.8.15
        contains a bug fixed in this release: after loading the file was not
        truncated to the last valid command, so the new commands are appended
        after a non well formed command. This means that:

        1) The first AOF rewrite triggered by the server will automatically
           fix the problem.
        2) However, if the server is restarted before the rewrite, Redis may
           not be able to load the file and you need to manually fix it.

        In order to fix a corrupted file you should start the redis-check-aof
        utility WITHOUT the --fix option, just to check the offset where the
        corruption is found. Around the offset reported by the check utility
        you'll find, inside your AOF file, a command which is not complete
        according to the Redis protocol. Just remove this incomplete command
        leafing the file unaltered before and after the offending command,
        and restart the server.

        IMPORTANT #1: Redis 2.8.15 is the only stable version of Redis with
        this bug so probably no actual real-world problem happened since the
        problem is automatically fixed at the first automatic AOF rewrite.

        IMPORTANT #2: Before upgrading to Redis 2.8.16, if you are using Redis
        2.8.15 with AOF enabled, make sure to trigger a manual AOF rewrite
        using the BGREWRITEAOF command.

* [FIX] SAVE is no longer propagated to AOF / slaves.

--[ Redis 2.8.15 ] Release date: 12 Sep 2014

# UPGRADE URGENCY: LOW for Redis, HIGH for Sentinel.

* [FIX] Sentinel critical bug fixed: the absolute majority was computed in a
        wrong way because of a programming error. Now the implementation does
        what the specification says and the majority to authorize a failover
        (that should not be confused with the ODOWN quorum) is the majority of
        *all* the Sentinels ever seen for a given master, regardless of their
        current state.
* [FIX] GETRANGE test no longer fails for 32 bit builds (Matt Stancliff).
* [FIX] Limit SCAN latency when the hash table is in an odd state (very few
        populted buckets because rehashing is in progress). (Xiaost and
        Salvatore Sanfilippo)

* [NEW] Redis is now able to load truncated AOF files without requiring a
        redis-check-aof utility run. The default now is to load truncated
        (but apparently not corrupted) AOFs, you can change this in redis.conf.
        (Salvatore Sanfilippo).
* [NEW] Sentinel: ability to announce itself with an arbitrary IP/port to work
        in the context of natted networks. However this is probably still
        not enough since there is no equivalent mechanism for slaves listed
        in the master INFO output. (Dara Kong and Salvatore Sanfilippo)

--[ Redis 2.8.14 ] Release date: 1 Sep 2014

# UPGRADE URGENCY: HIGH for Lua scripting users, the server could crash because
                   of a bug introduced in Redis 2.8.10, otherwise LOW.
                   LOW for Redis Sentinel.

* [FIX] Don't prevent use of shared integers if maxmemory policy is non-LRU.
        (Salvatore Sanfilippo)
* [FIX] Fail SYNC if background save child aborted due to a signal.
        (Yossi Gottlieb)
* [FIX] Different small redis-cli fixes. (Dov Murik, Charsyam, cubicdaiya,
        Kashif Rasul, Jan-Erik Rediger, Matt Stancliff)
* [FIX] AIX compilation fixes. (Siah Lyimo)
* [FIX] A number of other smaller issues.
* [FIX] Improved SIGINT handling (Matt Stancliff, Salvatore Sanfilippo)
* [FIX] Use unsigned types in SDS header to raise limit to 4GB.
        (Matt Stancliff, Salvatore Sanfilippo)
* [FIX] Handle signed/unsigned comparisons with more care around the code.
        (Salvatore Sanfilippo)
* [FIX] Colorized test output fixed to don't change the background color.
        (Mariano P辿rez Rodr鱈guez)
* [FIX] More Sentinel IPv6 fixes. (Eiichi Sato)
* [FIX] Deny CLIENT command in scripts. (Matt Stancliff)
* [FIX] Allow datasets with more than 2 billion of keys, initial work.
* [FIX] Fix a Lua scripting crash by storing the length of the static
        argv when first allocated. (Paddy Byers)

* [NEW] Pub/Sub PING. (Salvatore Sanfilippo)
* [NEW] Much faster ZUNIONSTORE. (Kyle Hubert, Salvatore Sanfilippo)
* [NEW] Faster ll2string() implementation. (Salvatore Sanfilippo)
* [NEW] **WARNING, minor API change**: PUBSUB NUMSUB: return type modified
        to integer. (Matt Stancliff)
* [NEW] redis-benchmark support for AUTH. (CharSyam)


(fhajny)