[FIX] account: avoid closing fiscalyear with unpost entries

As when closing fiscal periods, forbid to close a fiscal year with unposted entries.
Fixes #1194, opw 610784
[FIX] migration: allow debugging of migration scripts + avoid useless copies
[MERGE] forward port of branch saas-3 up to 3d4b82c
[FIX] stock: allow the user to use the '!=' operator in domains for 'Qty on Hand' and 'Qty available'. Fixes #2763
[FIX] correct typo introduce during forward-port in commit 388f1a1
[FIX] account: recordsets are not sortable in-place
[FIX] website: repair compatibility with 8.0rc1 carousel (banner) snippets that may be present in existing pages
[MERGE] forward port of branch 8.0 up to e883193
[IMP] mass_mailing: option to keep sent emails
[FIX] website: editor: ignore spurious changes for editable content

Changes to contentEditable or attributeEditable attributes
should not cause the corresponding section to be marked
as dirty (oe_dirty). This would otherwise cause an extra
editor save() for those, wrongly marking untouched
templates as `noupdate`, and possibly triggering access
right errors.
[FIX] website_sale: too tiny quantity input (if qty > 9)
[IMP] product: name_get matching on commercial_partner_id for suppliers

The name_get of a product will use some information (e.g. default_code) based on the supplier.
The matching of the supplier should use the commercial_partner_id in case the supplier info are on the company and the partner_id in the context belongs to the company (e.g. creates quotation with a contact of the company).
Fixes #1219
[IMP][TEST] event: auto confirmation option, allowing to
automatically confirm events. In a simple flow it is usefull to automatically
confirm event and registrations.

[TEST] event: moved draft2done test into a unittest, easier to finely tune
in order to test the auto confirm option. Moreover this gives a basis to
further add python tests in the module. Hooray.
[FIX] account_analytic_analysis: invoiced field takes customer invoices only

Besides, it subtracts customer invoices with customer refund invoices
[ADD] contribution files and image removed at 2ad092b
[FIX] auth_oauth: fb and google oauth providers reset on general settings apply

 - The res_config.xml file was missing in the manifest (so couldn't check the use of FB and Google OAuth from the general settings)
 - The default value for these oauth configuration were not set
[IMP] website: add snippet for floating picture
[IMP] event: refactored event form view. Usability reviews
showed that the form view was complicated and difficult to use. Now
that stat button and edition options in the front-end exist, it is
possible to remove some of the numerous tabs as well as some options
from the form view.

Coming: further cleaning of the model, behavior and probably the various
event-related views.
[IMP] ir_qweb: allow to display a datetime like a date
[FIX] Package: Windows: service name in setup.nsi