(cherry-picked from 383ab454725d9bf8d01392a587c8a2c0c2116294)
(Closes #2429)

- move the service product from product to hr_timesheet
- move default time unit for services from sale to account_analytic_analysis
to ease the configuration

This commit is related to d5115715

Closes #2440

[FIX] website_mail: can't edit mail templates

[IMP] sale_stock: warehouse_id field on sale order is now readonly, except in draft and sent states.

To allow display the login date according to the timezone of the user

- project kanban view: dashboard-like view, add sparklines for open tasks
and closed issues
- project: cleaned demo data, less stages
- project: description is now an html field

Error during forward port

[IMP] website_forum: tag creation now done only on enter, allowing to add whitespaces in tag name. More consistent behavior with odoo.

69297dbf

[MERGE] Domain name based multi website

This should be done later properly without polluting convert.py

When a module is updated, the sql constraints were checked against postgres pg_get_constraintdef() to see if they have diverged from the one defined in python code.
However this check was failing as the syntax returned by pg_get_constraintdef() (e.g. "CHECK ((credit * debit) = 0::numeric)") differs from the one returned by `unify_cons_text` method (e.g. "check(debit*credit = 0")) so the constraints were always dropped and recomputed.
This adds a definition column on ir.model.constraint (storing original defintion) to detect changes.
The pg_constraint is still inspected to make sure we detect constraint without ir_model_constraint but with postgres constraint defined (e.g. name_uniq defined in base.sql).

This changes also the date_update field when the definition changes.