Merge pull request #9 from schlitzered/fix_issue_8

switch from crc 16 to crc module

implement username

Dummy release

version bump to 0.2.2

performance improvements

modify commands to use byte type instead of string.

SentinelPool and SentinelHashPool cleanup:

- remove check if client is realy a master or slave

Add SentinelHashPool

enhancement: Connections Pools can now shrink

bugfix:  pass encoding correctly to the protocol parser

bugfix, if initial connect failed, mark connection as closed