v0.21.8

• Fix a crash if a client unsubscribes before subscribing
  #156.
• Fixed LevelUp and Memory persistence for offline messages, previously
  only one offline message per second was allowed.

v0.21.7

• Added the db option to Redis persistance
  #150.
• Fixed Redis persistence for offline messages, previously
  only the latest offline message was delivered
  #151.

v0.21.6

• Bumped MQTT.js dependency to v0.3.10.
• Bumped MOWS dependency to v0.0.6.

v0.21.5

• authorizePublish can return a Buffer to change the payload
  #146.
• Handled authentication errors
  #143.

v0.21.4

• Fixed wrong count of connected clients
  #135.

v0.21.3

• Fixed crash when started without a persistance.
• Emit will message if the keepalive timer fails.
• Wrapping mows for browserify when used in embedded mode.

v0.21.2

• Upgrade to MQTT.js 0.3.9.
• Fix authorization with binary credentials.

v0.21.1

• Added 'host' parameter to mosca.Server to specify the host
  to listen to.
• Added --host CLI option.

v0.21.0

• Fixed offline messaging
  #30.
• Bumped Ascoltatori to 0.15.0.

v0.20.3

• Fixed a packet duplication issue with Redis.
• Fixed a MongoDB error/crash with offline subscriptions.
• Added full MongoDB and Redis mosca.Server tests.