[FIX] Fix account_budget name unicode error

Fix bug https://bugs.launchpad.net/openobject-addons/+bug/1292245:
    Invoice budget's warning when crossovered budget lines are not related
    to any account will cause a UnicodeEncodeError if the account has
    unicode-only characters such as é.

Make sure that the budget name is a unicode to avoid UnicodeEncodeError
which happens when budget name contains UTF-8 characters.

Signed-off-by: Sandy Carter <sandy.carter@savoirfairelinux.com>

addons/account_budget/account_budget.py

@@ -22,6 +22,7 @@
 import datetime
 
 from openerp.osv import fields, osv
+from openerp.tools import ustr
 from openerp.tools.translate import _
 
 import openerp.addons.decimal_precision as dp
@@ -116,7 +117,7 @@ def _prac_amt(self, cr, uid, ids, context=None):
         for line in self.browse(cr, uid, ids, context=context):
             acc_ids = [x.id for x in line.general_budget_id.account_ids]
             if not acc_ids:
-                raise osv.except_osv(_('Error!'),_("The Budget '%s' has no accounts!") % str(line.general_budget_id.name))
+                raise osv.except_osv(_('Error!'),_("The Budget '%s' has no accounts!") % ustr(line.general_budget_id.name))
             date_to = line.date_to
             date_from = line.date_from
             if context.has_key('wizard_date_from'):