Rewrite binary jedis operations implementation

 Previously binary data was stored as `new String(byteArray)` but it is not correct - as stated in String javadoc, it can replace unmappable characters
Added comments regarding character encoding and sorting
MockPipeline refactoring - extracted text constants
Removed last String.getBytes() without explicitly specified charset.
Added javadoc for DataContainer.getBytes()
Merge pull request #21 from kshchepanovskyi/master

Rewrite binary operations implementation
update to latest jedis
fixes for strlen and sdiff