closes #4768

When searching products for a specific category, display the products of the whole category subtree.

Add restriction on product_id field to prevent the suppression of the product
if already present in an invoice.
This is to avoid the suppression of a used product variant when modifying
the list of attributes.#
Due to the constrain, the variant will be disabled instead of deleted.
Fixes #4129

Add warning message on the product form to warn users about the potential impact
of modifying variants.

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.

name was confusing for bom and product if the value of the attribute is display without the attribute name
added key in context to keep the previous behaviour (e.g. in product view where the attribute name is present)

Add readonly attribute to avoid sending both factor and factor_inv value to the backend when saving.
This was possible if the user switched between uom_type to fill the two fields.

Remove the hardcoded precision of 12 on factor and factor_inv,
to use the complete natural precision of NUMERIC types,
preserving all significant digits.

e.g. a UoM with a factor_inv of 6.0 used to be computed as:
factor_inv: 6.0 -> factor: 0.166666666667 (1.0/6.0, rounded to 12 digits) -> factor_inv: 5.999999999988 (1.0/factor)
which could lead to errors such 12*0.166666666667 = 2.000000000004 instead of 2.0

Slightly changed the way the ORM handles float fields to allow setting `digits=0`
as a way to explicitly require a NUMERIC value but without enforcing/rounding
the values at the ORM level, i.e. a truly full-precision field.

NUMERIC type has unlimited precision but is less efficient so should not be
used as the default behaviour, which is why we keep float8 as an alternative.

Modified the view to display the product UOM factor with a 5 digits value by default.
This value is for usability purpose only, the field still accepts bigger precision, by
setting the `digits` option on the field in the form view.

This change is safe in a stable series, the `digits=0` alternative is
treated the same as the default `digits=None` everywhere in the framework,
except when creating the database field.

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

[IMP] Set custom EAN not visible when multiple variants

[IMP] Change landed costs views + make ean visible upon creation

[IMP] Typo

Was missing to be used in domain added at 92d8f15a.
Fixes #2570

[FIX] product: Even when the product template has more than 1 variant, the default_code is displayed.

At 96f038a6 product-related fields were removed due
to an important product.template/product.product
refactoring. As the field values were simply
dropped, they may not be nullified when upgrading an
existing database. Forcing them to False will take
care of it.

[FIX] product: don't display 'create and edit' option on many2many_tag to create variant on product_template. The quick create is confusing for users

[IMP] Counterpart locations and weights should not be read-only in case of type service, but should simply be invisible as the other fields

Was removed (for unknown reason) during refactoring of product and template (opw 611699)

product.product reuses most of the product.template views however some parts need to be excluded or replaced.
Instead of adding template only parts in base view and removing it for product, split the views in 'common' (product_template_form_view), 'template only' (product_template_only_form_view) and 'product only' (product_normal_form_view) where the first is inherited by the other two. The attribute mode='primary' on both second views allows to make sure that future inheritance of product_template_form_view and product_template_only_form_view will work with the full rendered product_template_form_view view.
This allows us to have valid buttons in crm for bill of material (filters based on active_id).
Also cleaning the mess with circular dependencies.

The lst_price field on product.template is a related to list_price. As we do not allow to set a value for related fields at creation (see orm.py , L4180), we display the list_price instead (float field).
On the product.product form, we display the lst_price (function field, readonly) as we don't want to allow changing the template price from the product. opw 609497

[FIX] product: add menu item to attributes and attribute values. Adding constraint to prevent deleting attributes with references to products.

[IMP] product: rename fields variant_ids into attribute_line_ids on the template and attribute_value_ids on the product.

[IMP] product: refactoring of product variant. The main view became the view of product template and the product product (or product variant) are created with the variant values combinaison. Bom is splitted into bom and bom line and can use the variant combinaison.

bzr revid: rim@openerp.com-20140422100306-bj8jxlatjmko4oi5

bzr revid: rsi@tinyerp.com-20140411131842-9zppvrs2szqa4o47

[FIX] product, stock: set active field in default product view, instead of inherited view of stock module

The active field was placed in the Delays section, which does not make sense
Besides, we should be able to disable products by default, not when stock is installed.

bzr revid: dle@openerp.com-20140408180920-jpl50ups6ro1z4qp

bzr revid: jco@openerp.com-20140320140959-d2mr2aic4ei0j5h1

bzr revid: jco@openerp.com-20140320121335-cnjfecg115t8fa7t

bzr revid: odo@openerp.com-20140304182724-kplzfik56ebp2boe