optionally use lua scripting for cache cleaning (_removeByMatchingAnyTags method) configurable by the new "use_lua" backend setting (turned off by default).
CAUTION: requires commit 1c101cf5543624 to CRedis submodule in order to work properly.
Merge pull request #50 from nemphys/lua-clean

optionally use lua scripting for cache cleaning (_removeByMatchingAnyTags method)...
Track latest Credis_Client. Refs #50
Fix first run when LUA script does not yet exist. Refs #50
Fix log message.
Wrap CredisException with Zend_Cache_Exception in clean(). Track latest Credis_Client.
Track latest Credis_Client, use evalsha+eval rather than script exists+evalsha.
Always return after lua cleaning script execution, otherwise we will do the job twice (lua and non-lua)
Support lz4 compression library (through php-ext-lz4, https://github.com/kjdev/php-ext-lz4)
Merge pull request #51 from nemphys/lua-fix

Always return after lua cleaning script execution, otherwise we will do the job twice (lua and non-lua)
Merge pull request #52 from nemphys/comp-lz4

Support lz4 compression library (through php-ext-lz4, https://github.com/kjdev/php-ext-lz4)
Optimize cache saving code in situations when a cache tag is assigned to the same key more than once
Merge pull request #53 from nemphys/array-opt

Optimize cache saving code in situations when a cache tag is assigned to...
Also use a lua script for saving cache entries (if use_lua is enabled in config); performs slightly better than the normal way and provides atomicity when using phpredis.
use a lua script for garbage collection (if use_lua is enabled in config)
Combine both versions of cache cleaning lua script in one.
Merge pull request #58 from nemphys/lua-cleanup

Combine both versions of cache cleaning lua script in one.
Merge branch 'lua-gc' of https://github.com/nemphys/Cm_Cache_Backend_Redis

Conflicts:
	Cm/Cache/Backend/Redis.php
Track latest Credis_Client.