[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
[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] 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
[FIX] ir.mail.server: restore parsing of multiple RFC2822 addresses including non-ASCII chars

Rev f2cf6ced1 modified RFC2822 parsing in order to better support
unicode characters inside the Name part of an address header.
However the patch broke handling of multiple addresses (comma
separated) - silently discarding all recipients except the
first one, as soon as any non-ASCII character was present.

This patch restores the functionality while preserving the
fix from f2cf6ced1, and simplifies the code using email.utils
utility functions.

Fixes (again) lp:1272610, OPW 607683
[MERGE] Forward-port 7.0 up to 1b49a87
[FIX] web_diagram, unlink connectors/transitions between nodes from the diagram view (transitions IDs sent to the web client were strings instead of integers)
[FIX] incorrect qweb interpolations

unnecessary, worked by accident and broken by change to interpolation regex in 35f5fb46
fix typo
[FIX] README: grammar
[FIX] CONTRIBUTING: dead link
[FIX] models: do not prefetch fields to recompute, and recompute once only

The method _prefetch_field() was accidentally prefetching fields to recompute;
which was skipping the actual recomputation, since a value was put in cache.
But sometimes the field's value was fixed by an extra recomputation of the
field.  Here we remove the extra recomputation and fix the cache corruption.
[FIX] website_membership: crash when member has no country

in memberships countries list