[FIX] bus, im_chat, im_livechat : use correct session to rpc call, little refactoring of im_livechat js, and prepare js code for Odoo Support.
[FIX] base_gengo, website_gengo: groups on the gengo key.

Basically the admin group can read the gengo key. When adding website_gengo that adds the
website groups, the groups allowed to access the key are updated.

This is done because in base_gengo the website groups are not necesssarily defined. Website
is not a dependency of base_gengo.
Merge branch '8.0' of https://github.com/odoo/odoo into 8.0-linux64