[FIX] product: creation of reference uom

Set a default value for factor when creating a new uom.
Could not create a new UoM with type reference (if creates a reference uom, no need to pass a factor).

Change the readonly filter to (type = bigger) to make the field writable for reference uom.
This is needed to force the reset of the factor when switching of type (onchange_type).
As the field was readonly, kept the old value for factor.
[FIX] project_timesheet: date of created analytic line not in user tz

When the user was in timezone UTC + 1, and added a project.task.work which created an analytic entry line (timsheet activity), if the datetime was set to 11/25 00:00:00, the date on the analytic line was set to 11/24, because this was the truncated stored value(UTC Time), which was 11/24 23:00:00
[FIX] account: prevent invoice line duplication on partner duplication

If a company contact (a partner with a company set as parent) had invoices, and the company of this contact was duplicated, all the invoices lines were duplicated,  on the original invoice moreover (new lines were added on existing invoices)
[FIX] marketing_campaign: typo in manifest
[FIX] l10n_br: remove reference to old base.group_extended group

Fixes #3879
[FIX] mrp: prevent recursion from phantom boms with no lines

if the bom is phantom and has no line, we attempt to find a new bom with the default product uom
This is possible that we find the same bom that the current one
In such a case, we must not explode, to avoid recursion.
[FIX] correctly update many2many in listview (web client)

Fixes the issue #1216 (follow the link for more information). The issue
was caused by a hack in list view: the magical suffix __display is used
in render_cell to determine if a many2many field should be updated. This
commit simply makes sure that old many2many fields + __display keys are
cleared.

A better way would be to redesign/refactor the list view to avoid that
hack in the first place.  But this would be a much more complex task.
[FIX] stock: prevent serial number deletion on stock.move

prodlot_id field may be required due to constraint `_check_tracking`.
When a stock.production.lot is deleted, the constraint on linked stock.move is
not checked. To avoid inconsistency, restrict the suppression.
To allow the modification of existing stock.move, remove the states attribute on
the field definition.

As removal of serial may impact the traceability, it makes sense on buisness
point of view to force the modification of previous stock.move, even if the
constraint would not have been violated.
The list of linked stock.move is present on the serial form view making
the operation easier.

Fixes #3560, lp:1176912
[FIX] base: avoid having 'False' in name of a bank

The name_get of res.partner.bank uses the format_layout to generate the name
of the bank. As every field is not required, we may get 'False' in the name.
Replace these missing values by an empty string.

Fixes #3590
[FIX] stock: on stock picking invoicing, allow to pick a journal if no move line
[FIX] product: remove unnecessary UoM rounding step, add missing test

Remove the intermediate rounding inside _compute_qty(), as it
is not necessary after rev. fa2f7b86 and has undesired side-effects.

An extra float_round() operation inside _compute_qty()
had been added at rev. 311c77bb to avoid a float representation
error in UoM factors that could bias the ceiling() operation
done as the last conversion step.

Example 1:
Dozen has a factor of 1/12, which was previously stored in the
database with a decimal accuracy of 12 significant decimal digits.
This meant the factor was exactly stored as 0.08333333333333.
When reading this back into a Python float, the precision was not
sufficient, and the UoM conversion of 1 Dozen to Units gave a
result of 12.00000000000047961...
After the final ceiling() operation to Unit's rounding, the
converted value ended up as 13.

This problem was initially solved using an extra rounding.

However at revision fa2f7b86 the decimal precision used to store
UoM factors was increased to preserve all significant digits.
This added the extra precision necessary to read the Dozen factor
back into an accurate float value of 1/12, and the conversion of
1 Dozen now gives 12.0 Units, even without the intermediate
rounding operation. (Works for other factor values too)

At the same time that extra rounding operation has undesired
side-effects, as it requires a fixed precision derived from
the rounding precisions of the UoMs. But there is no given precision
that would work in all cases for this intermediate value. It is
always possible to find a valid combination of UoM roundings
that breaks that intermediate step, e.g. by forcing integer
roundings.

Example 2:
Let Grams have a rounding precision set to 1 because no smaller
quantities are allowed, and Kilograms a rounding of 0.001 to allow
representing 1 Gram. (gram factor = 1000 and kilogram rounding = .001
by default)
If we try to convert 1234 Grams into Kilograms, the extra rounding
introduced in 311c77bb will cause a rounding of 1234.0/1000.0 at
the precision of Grams (1), which gives 1.0 as a result.
The net result of this conversion gives 1234.0 Gram = 1.0 Kilogram,
while the correct result (1.234 Kilogram) is perfectly compatible
with the UoM settings.

Similar errors could be triggered with various rounding settings, as
long as the intermediate rounding needs a finite precision.

Two extra tests have been added to cover Example 1 and Example 2.

--
Related to #2072, #1125, #1126, #2672
Closes #2495, #2498