[FIX] website_forum: allow moderators to see misbehaving user profiles

This is to help forum moderators to fight against
spammers. It was previously difficult as the spammer
profile became unreachable as soon as their karma
went below 1, even if they had other questions
or answers still published.
[FIX] website_forum: restore bind to onclick because CKE Editor uses it, so on('click', fun) breaks things.

Fixes bugs with z-index error on some popups (image selector for example...)
[FIX] website_forum: fix error 500 when editing an answer

Was caused by missing tags.
Also fix also backwards-compatibility for textext selection method.
[FIX] website_forum: use other attr than value to init select2

The backend would otherwise fail because the value has been already processed
Merge branch '8.0' of https://github.com/odoo/odoo into 8.0-linux64