This commit implements UNLINK for Redis, RedisCluster, and RedisArray.
To a client library UNLINK behaves identically to DEL so we can use the
same handlers for both.
While testing example code for Geo codes I discovered that passing
a negative count would cause PhpRedis to hang as it would send an
invalid number of arguments to the server.
This commit is adding support of data compression.
LZF was choosen because it small and fast and Redis server uses it.
Since [pecl package](https://pecl.php.net/package/lzf) doesn't provide
lzf.h file after installing, LZF library was added as submodule.
Another algorythms may be easely added by analogy with serializers.
TODO: unit-tests for different data types.
* Added a test specifically for RedisCluster to test slave failover
settings.
* Added an option to specifically disable colorization, as well as
a mechanism to determine if the output is being piped, such that
we can turn colorization off in that case as well.
* Fixed getLastError() to look at redisCluster->err, rather than flags
* Fixed serialization bug for zipstr multibulk processing
* Added specific RedisClusterTest tests for SCRIPT and EVALSHA commands
All unit tests passing now! \o/
* Updated the unit test suite to print each unit test method name we're
running as we do so, and also with fancy colors :-)
* Added functionality to handle failed transactions, where Redis will send
us a multi bulk length of -1. This can happen because of an EXECABORT
error, or because a watched key was modified during the transaction
* Initialize serialized return value to NULL to avoid segfault
* use strtol not atoi in our long response handler, to handle large values
* Fixed our return value in multi responses
* Fiexed type() command as cluster doesn't still have the '+' prefix when
checking for what TYPE returns
* Exists should return a BOOLEAN not 1/0
* Fixed sRandMember to work in the context of a MULTI block
* Use "LINDEX" not "LGET" as "LGET" isn't a valid Redis command
* Properly set our slot for the PFCOUNT command
* Many unit test changes such that Redis and RedisCluster are happy using
mostly the same ones.
* Continuing to hammer through Redis unit tests such that the
tests will work for both Redis and RedisCluster objects
* Fixed mset so we return the RedisCluster object when it's
executed in multi mode.
