add support for 'connect_timeout' option for redis arrays

Add "connect_timeout" option to RedisArray constructor, and redis.arrays.connecttimeout php.ini setting.

Value is a double and specifies timeout in number of seconds when creating redis socket connections used in the RedisArray.

Sample Usage:
-----

$redisArray = new RedisArray(
	array(
		"127.0.0.1:6379"
	),

	array(
		'index' => true,
		'connect_timeout' => 1.5
	)
);