handle missing JS files with a console log
[FIX] mrp: better selection of bom

When searching for a bom based on a product.product, the method used to return any bom linked to the template (so searching for bom for variant A could return bom for variant B if both share the same product.template).
This will allow to return bom not linked to a variant without returning the one of another variant (opw 609358)
[FIX] calendar: avoid double 'Attendees' field in search view

The partner_ids fields represents attendees but it's confusing to have twice the same field in search view (opw 607275)
[FIX] slug: fallback to positive ID when slug appears to contain a missing negative ID

Cherry-pick from dcac4cc0dfd4412e1139399fb17ec7ba6118aad4
[FIX] sale: quote character in company name is converted to html entity

Avoid to get company names such as "L'abc" to be transformed as "L&#39;abc" opw 607221
[FIX] web: tooltip container set to body in all case

Mandatory since we changed the structure of the dom since 8.0.
[IMP] point_of_sale: add an error sound to the error popups
[IMP] point_of_sale: a little explaination of how the barcode pattern system works
[IMP] point_of_sale: improved rendering speed of the partner list
[FIX] point_of_sale: order invoicing was broken
[FIX] point_of_sale: it was impossible to delete a pos session
[IMP] point_of_sale: show traceback popup when there is a server error when posting orders (which should NEVER happen !)
[IMP] point_of_sale: add debug popup that displays unsent order data, for when localStorage is hard to inspect

Conflicts:
	addons/point_of_sale/static/src/js/widgets.js
[IMP] point_of_sale: add a debug option to delete all unsent orders
[IMP] point_of_sale: add a basic UI unit test based on the new 'Tour' module
[IMP] point_of_sale: forgot changes in this file in the previous commit that introduced unit tests
[IMP] point_of_sale: tests work better when they are loaded and run by the unit test system!
[IMP] point_of_sale: made the server data loading more modular for easier development of point_of_sale extensions
[IMP] point_of_sale: report errors when loading the point of sale with a traceback and a nice popup
[IMP] pos_discount: a new pos extension that allows you to quickly give a global discount on the current order