• add auto_release option to release all locks when the manager object
  is destroyed (from Ryan Bastic)
  
• add logger option for a callback to log errors (from Ryan Bastic)
  
• catch errors on connect (from Ryan Bastic)
  
• make sure encoding is disabled for Redis connections
  
• make sure the initial number of connections is high enough
  
• allow release() to be called with unnamed arguments