[FIX] mass_mailing: updated link conversion.

Previously to this fix, url matching the same base url were linked to
the same shortened url: foo.be -> /aaa, foo.be/bar -> /aaa/bar instead of
a new shortened url.
[REM] hr_holidays: dead file
[FIX] mail : fix style (css, js and xml) of topbar button of mail.compose.message
[IMP] im_chat, im_livechat : usability improvements like, adding smiley, replace uuid by session name in reporting, modify messages order for the session form view and disabled beep when you receveive your messages.