Expose *SCAN commands to BinaryJedis

This PR would resolve #573.

We implement *SCAN commands to BinaryClient, but not BinaryJedis.
This PR exposes *SCAN commands from BinaryJedis.
(Sure it aims only String cursor versions.)

Unit tests also included.

Please review and comment it!

Thanks! :)

ChangeLog
====
* method signatures are a bit similar to Jedis's *SCAN
  * but it takes parameters to byte[] instead of String
* ScanParams : allow match pattern with byte[]
* ScanResult : add method to get cursor with byte[] type
  * SCAN for BinaryJedis unit tests included