[REM] db_manager: remove old dependencies to datejs and timepicker and replace by momentjs
[IMP] website_forum: better implementation of automatic nofollow attribute
on links in forum posts.

This is now done when creating / updating posts instead of updating the display
of the post. This means that old posts may contain nofollow attribute altough
the user has sufficient karma; however it is acceptable compared to the computation
we save by avoiding processing every post to display.
[IMP] ir.attachment : move the fields index_content (from document), mimetype and datas_checksum (from website) to base. In base, the mimetype is computed with the Magic python lib (if installed, else with a custom function using magic number), and the index_content is an implementation of strings unix command. In document, index_content is still computed with the indexer of document module.
[IMP] ecommerce onboarding misc improvements: tour, qty inc/dec, add placeholder for product desc bottom of add to cart button, add print button, cart icon fix for all themes, and last delivery module menu add to sale, so now both sale or warehouse delivery menu with access right stock.group_stock_manager and base.group_sale_manager, move from demo file to data file set for default one data as a delivery courier.