Support for SENTINEL commands

I have added SENTINEL related methods to Jedis class down to Protocol via Client and BinaryClient classes.

Probably instead of having so many new methods one could have SentinelParams class (just like SortingParams for sort). 

At the same time was not sure about  checkIsInMulti() - should it be in every call now? Most does not apply to SENTINEL methods as MULTI is [not allowed](http://redis.io/topics/sentinel).

Test based on config files taken from [noise/redis-sentinel-tests](/noise/redis-sentinel-tests).

Time to build [hamsterready/jedis-sentinel-pool](/hamsterready/jedis-sentinel-pool)  - still might need to refactor JedisPool as it is not extendable (non empty constructors are evil ;-)).