[FIX] web: wrong tooltip display for long menus

Due to the switch to Bootstrap 3.2 in this version, tooltip auto placement works erroneously (see https://github.com/twbs/bootstrap/issues/13897).
This is a workaround, waiting for a fix in Bootstrap assets.

(Closes #1341)
Merge branch '8.0' of https://github.com/odoo/odoo into 8.0-win32