[IMP] Cleanup and refactoring of exception handling

Unify and refactor exception handling in framework and addons.

The generic `except_osv` is now deprecated, and replaced by more specialized exception subtypes:
 - `UserError` (renamed from Warning, as it conflicts with the built-in `Warning`) raised when a non-technical error occurs during a business operation. It could be a missing information in the data provided by the user, or a misconfiguration.
 - `AccessError`: raised when any operation is denied because the user conducting it does not have the required access rights.
 - `AccessDenied`: raised when an operation that requires authenticated access is attempted via an unauthenticated request.
 - `MissingError`: raised when an operation is attempted on a record that does not exist.
 - `ValidationError`: raised when an operation violates a SQL or Python constraint.
 - All other exceptions are internal errors due to a system problem or bug, and raised untouched to the client-side, which should display a traceback.

All exceptions take a single message argument.

The `test_exceptions` module has been updated to showcase both new and old (deprecated) exceptions.

A great many old `except_osv` had a useless title with "Error!" or "Warning", those have been removed, as this is handled by the client-side widget that displays the messages.

This commit introduces a more consistent policy for logging errors and warnings:
 - All messages that do not require administrator attention should be logged at INFO level or lower. This includes all errors that are notified to the user in a friendly manner, even for access right problems or validation errors during business operations.
 - All messages that indicate a likely misconfiguration or malicious use by the users should be logged at WARNING level, as they typically require administrator attention.
 - All other unhandled internal errors cannot typically be handled by the user and should be logged at ERROR or higher level, as they require immediate administrator attention.

1 files changed, 3 insertions, 2 deletions

diff --git a/addons/analytic/models/analytic.py b/addons/analytic/models/analytic.py
index 6d7423d1adf..227683f8bd0 100644
--- a/addons/analytic/models/analytic.py
+++ b/addons/analytic/models/analytic.py
@@ -26,6 +26,7 @@ from openerp.osv import fields, osv
 from openerp import tools
 from openerp.tools.translate import _
 import openerp.addons.decimal_precision as dp
+from openerp.exceptions import UserError
 
 class account_analytic_account(osv.osv):
     _name = 'account.analytic.account'
@@ -157,7 +158,7 @@ class account_analytic_account(osv.osv):
         for account in self.browse(cr, uid, ids, context=context):
             if account.company_id:
                 if account.company_id.currency_id.id != value:
-                    raise osv.except_osv(_('Error!'), _("If you set a company, the currency selected has to be the same as it's currency. \nYou can remove the company belonging, and thus change the currency, only on analytic account of type 'view'. This can be really useful for consolidation purposes of several companies charts with different currencies, for example."))
+                    raise UserError(_("If you set a company, the currency selected has to be the same as it's currency. \nYou can remove the company belonging, and thus change the currency, only on analytic account of type 'view'. This can be really useful for consolidation purposes of several companies charts with different currencies, for example."))
         if value:
             cr.execute("""update account_analytic_account set currency_id=%s where id=%s""", (value, account.id))
             self.invalidate_cache(cr, uid, ['currency_id'], [account.id], context=context)
@@ -269,7 +270,7 @@ class account_analytic_account(osv.osv):
     ]
 
     def name_create(self, cr, uid, name, context=None):
-        raise osv.except_osv(_('Warning'), _("Quick account creation disallowed."))
+        raise UserError(_("Quick account creation disallowed."))
 
     def copy(self, cr, uid, id, default=None, context=None):
         if not default: