Release 0.11.0

• Add event callback for events like slotmap updated.
• Add connect callback for the sync API.
• Add connect function in the async API for fully asynchronous startup.
• Update the slotmap asynchronously in the async API.
• Follow MOVED redirect and update slot mapping concurrently.
• Update slotmap on error.
  When connect failed, update slotmap instead of sending command to random node.
  When command fails (timeout, etc.) schedule slotmap update for next command.
• Update slotmap when redisClusterCommandToNode() fails.
• Correct parsing of an IPv6 address in an ASK redirect.
• Correct handling of XREAD and XREADGROUP.
• Rename of some types and functions.
  (Old names are still defined by default for backward compability.)
• Update hiredis to v1.2.0 when the CMake build handles the download.
• Build improvements.