[FIX] account: do not validate move when novalidate is in context

The key 'novalidate' is added in the context when an operation not impacting
the validation of a move is made. The validation recreates analytic lines
which decrease the performances.

In case of registrating a payment, the skipped validation are the one from
the reconcile method (reconciliation does not change the validity)
Fixes #3787, opw 618529
[FIX] tour.js: popover position when scrolling down
Merge branch '8.0' of https://github.com/odoo/odoo into 8.0-linux64