* [8.0][mass_mailing] some fixes
* [FIX] rename wrong mailing_type field and add missing fields when creating a mass mailing from the composer
* [FIX] coerce tooltip to an unicode string to avoid a json crash when locale produces a non unicode string for strftime(%B)
* [FIX] repair wrong sql statement computing statistics
[FIX] point_of_sale: report, product_id of line is product_product

product_id column of pos_order_line is a product_product
the left join of l.product_id was done on product_template, instead of product_product

It worked as long as the ids product_product were the same as product_template. Meaning that, if you used variants, this report view was screwed.
[IMP] account_budget: added date filter in print budget report

Fixes #1743, opw 611307
[FIX] base: wrong model change check

Comparing an id and a browse record will always fail so the exception would have always been raised when changing a model (e.g. updating a module with custom fields).
[FIX] note: small bugs
[IMP] Location of extra moves should be matched
[IMP] Only one incoterms item
[IMP] Buttons should not be usable by purchase manager that is no stock user
[IMP] Counterpart locations and weights should not be read-only in case of type service, but should simply be invisible as the other fields
[IMP] Change help message package setting
[FIX] ir_model: invalidate cache when adding new fields

When a new ir.model.field is created, add the new field in the fields_by_model (cache of custom fields). This is required as the __init__ method would not retrieve the new field if fields_by_model is already set.
Otherwise, the _columns would not contain the new fields and we could not access it without restarting the server (e.g. the installation of a module adds ir.model.fields and use it in the a view.
[IMP] Use correct field for showing red lines for late pickings in tree view
[IMP] Add partner_id and invoice control to picking tree
Forward port of branch 7.0 up to 0ab88f5
[IMP] Better to have corresponding lates
Forward port of branch saas-3 up to 7bcefaf
Forward port of branch saas-4 up to rev 15a3a2a
Forward port of branch saas-5 up to rev 4895281e
[IMP] osv/fields.py: improve code change of rev eea07e27
[FIX] calendar: dropdown button misaligned

+ add meaningful placeholder