[trunk] accents block usage

[Ruud Riem-Vis]

I've seen bug 613721 and this is probably related. I want to define products after I've defined product categories.
Trying to avoid the bug 613721, I've renamed all product categories to avoid the use of any accents but still the problem remains (and occurs both on web and GTK client).

Traceback (most recent call last):
  File "/usr/local/lib/python2.6/dist-packages/openerp-server/netsvc.py", line 435, in dispatch
    result = ExportService.getService(service_name).dispatch(method, auth, params)
  File "/usr/local/lib/python2.6/dist-packages/openerp-server/service/web_services.py", line 586, in dispatch
    res = fn(db, uid, *params)
  File "/usr/local/lib/python2.6/dist-packages/openerp-server/osv/osv.py", line 57, in wrapper
    return f(self, dbname, *args, **kwargs)
  File "/usr/local/lib/python2.6/dist-packages/openerp-server/osv/osv.py", line 135, in execute
    res = pool.execute_cr(cr, uid, obj, method, *args, **kw)
  File "/usr/local/lib/python2.6/dist-packages/openerp-server/osv/osv.py", line 125, in execute_cr
    return getattr(object, method)(cr, uid, *args, **kw)
  File "/usr/local/lib/python2.6/dist-packages/openerp-server/osv/orm.py", line 1707, in fields_view_get
    xarch, xfields = self.__view_look_dom_arch(cr, user, result['arch'], view_id, context=context)
  File "/usr/local/lib/python2.6/dist-packages/openerp-server/osv/orm.py", line 1369, in __view_look_dom_arch
    fields_def = self.__view_look_dom(cr, user, node, view_id, context=context)
  File "/usr/local/lib/python2.6/dist-packages/openerp-server/osv/orm.py", line 1356, in __view_look_dom
    node.set('string', trans)
  File "lxml.etree.pyx", line 634, in lxml.etree._Element.set (src/lxml/lxml.etree.c:31548)
  File "apihelpers.pxi", line 487, in lxml.etree._setAttributeValue (src/lxml/lxml.etree.c:13896)
  File "apihelpers.pxi", line 1242, in lxml.etree._utf8 (src/lxml/lxml.etree.c:19848)
ValueError: All strings must be XML compatible: Unicode or ASCII, no NULL bytes

This bug is very annoying and makes it impossible to define any products (at least for the french version I've tested).