Track credis 1.9.1 (fixes PHP <5.6).

Track latest Credis library (1.8.2).

Also send reads to the master when load_from_slaves is '2'.

Merge pull request colinmollenhour#122 from luckyraul/master

Fix auth 1.10

Improve README docs on new HA and load balancing features. Fixes coli…

…nmollenhour#112

Merge pull request colinmollenhour#111 from mpchadwick/ee-pagecache-w…

…orkaround

Add Auto Expiry Feature

Add autoload declaration for Magento 2.

Track lastest lib/Credis.

Merge pull request colinmollenhour#102 from Xon/latest_credis

Track latest Credis

Fix unit tests. Track latest Credis.