Squashed commit of the following:

commit 9f10704836c062319bd29b26d5b10811b843bfff
Author: vmorsiani <vmorsiani@gmail.com>
Date:   Fri Aug 8 08:59:28 2014 +0200

    remove smack dependency from extension-api

commit f14cd630c2a6082d8c77cd5aa4690e41e4c0dc6b
Author: vmorsiani <vmorsiani@gmail.com>
Date:   Wed Aug 6 23:21:33 2014 +0200

    ease sendMessage to chatroom + remove unused imports