Hi all,
I would add my extension in xwiki-contrib.
This allows to use the mantis soap client in a macro.
My first code
https://github.com/jerr/xwiki-extension-mantis seems to work
(my github account is jerr).
According to my understanding of
http://contrib.xwiki.org/xwiki/bin/view/Main/WebHome this email is the
first step.
Tell me if you need more information.
Regards,
Jeremie.