[FIX] stock: groups mixup in views

Use group_production_lot for serial options, group_stock_packaging for packaging, use group_tracking_lot for pallet/parcel
Groups are removed completly from the view for stock.tracking as they render the view useless.

Always display weights on the product form
They really have nothing to do with the logistic units and we don't have another group to restrict them to.

Fixes #1443
[ADD] l10n_lu: abbreviated financial reports

Abbreviated version of the p&l and balance sheet reports
[FIX] account: self typo
[FIX] gamification: on delete badge user, cascade

Otherwise, this is no more possible to delete users having badges
[FIX] ir.ui.view: creating custom views in backend did not compute view type

When creating new records in backend all field values are
sent to the server, including empty fields.
[FIX] account: precision_get returns a number of digits

In other words, it returnes a precision digits, not a precision rounding
[MERGE] forward port of branch 7.0 up to 03df412f
[ADD] doc: workflow doc from v7+ (saas-5)

I tried starting a better one, but the workflow code is a complete mess so I
have no idea how this thing works without significant study and testing.

Thus, not trying to write a brand new and complete doc, maybe later.
[IMP] mail: parsing emails with several html parts

If an email contains several text/html parts inside a multipart email, the previous code was only keeping the last content part.
The Content-Type: multipart/mixed allows several independent part (RFC1341 7.2.2), so two html is technically valid.
With this patch, the two parts are concatenated. (opw 614755)

Modify append_content_to_html regex to make sure the regex keeps the content of the html instead of removing it.
e.g.: "123 <html> 456 </html> 789" used to be stripped to "123  789" while we expect "123 456 789"
[FIX] barcode_interface: when loading widget, picking_type_id was sometime not correctly set
[IMP] fields: do not copy field objects anymore, but make new instances instead

Because of the parameter overriding mechanism implemented by fields, it is no
longer necessary to copy field objects.  It is even better to no copy them in
the case of related fields.
[IMP] fields: rename attribute 'copyable' into 'copy'
[IMP] doc: add testing reference and improve docstrings
[FIX] web: destroy modal on cross click or escape

Instead of just hidding it
Otherwise, when opening a new dialog, it is considered that there is a previous opened dialog, and this can lead to refresh the record which opened the hidden/previous dialog

This is related to rev. 57b48602fb7afa5d0539e8d0caa8d1e10c3910e5
[FIX] models: in _create() and _write(), mark fields to recompute earlier

An issue occurs when a constraint is checked before computed fields are marked
for recomputation: the constraint will read the field's current value, which
may be wrong.  If the field is marked soon enough, the constraint will trigger
the recomputation and use a correct value.
[IMP] fields: do not force required=True on related fields

This may cause issues if the field is stored: non-null constraint will prevent
saving records when no value is provided.
only use alpha channel if it exists
[FIX] point_of_sale: printing of tax name on hardware was missing data 'name', also made the regular print use the same value for consistency.
[FIX] res.users: exactly match login when operator in ilike, equal
[FIX] account_invoice: using has_group to determine if user has group group_supplier_inv_check_total

has_group do not care about the fact res.groups is access restricted