Change log pub sub (#143)

* PubSub protocol support
Added support for :
- XEP-0050   (Command))
- XEP-0060   (PubSub)
- XEP-0004   (Forms)

Fixed the NewClient function by adding parsing of the domain from the JID if no domain is provided in transport config.
Updated xmpp_jukebox example

* Delete useless pubsub errors

* README.md update
Fixed import in echo example

* Typo

* Fixed raw send on client example

* Fixed jukebox example and added a README.md

* Changelog v0.4.0

CHANGELOG.md

@@ -1,5 +1,19 @@
 # Fluux XMPP Changelog
 
+## v0.4.0
+
+### Changes
+
+- Added support for XEP-0060 (PubSub)  
+(no support for 6.5.4 Returning Some Items yet as it needs XEP-0059, Result Sets)
+- Added support for XEP-0050 (Commands)
+- Added support for XEP-0004 (Forms)
+- Updated the client example with a TUI
+- Make keepalive interval configurable #134
+- Fix updating of EventManager.CurrentState #136
+- Added callbacks for error management in Component and Client. Users must now provide a callback function when using NewClient/Component.
+- Moved JID from xmpp package to stanza package
+
 ## v0.3.0
 
 ### Changes