[FIX] web_editor, translate: xml translate encoding

lxml.HTMLParser detect the content encoding by itself if not specified.

in the issue leading to this fix, content in a mail with u'\xa4'
( ) was transformed intto u'\xc2\xa4' ( ) since HTMLParser
selected the wrong encoding (latin-1 instead of utf-8 for example).

this commit specify the known encoding and revert 3d00c210f which was
another attempt at this issue.

addons/web_editor/static/src/js/backend.js

@@ -307,15 +307,7 @@ var FieldTextHtml = widget.extend({
             return this.editor.save();
         } else if (this._dirty_flag && this.editor && this.editor.buildingBlock) {
             this.editor.buildingBlock.clean_for_save();
-
-            // escape text nodes for xml saving
-            var $escaped_el = this.$content.clone();
-            $escaped_el.find('*').addBack().not('script,style').contents().each(function(){
-                if(this.nodeType == 3) {
-                    this.nodeValue = _.escape(this.nodeValue);
-                }
-            });
-            this.internal_set_value( $escaped_el.html() );
+            this.internal_set_value( this.$content.html() );
         }
     },
     destroy: function () {

openerp/tools/translate.py

@@ -271,7 +271,7 @@ def xml_translate(callback, value):
         return trans.get_done()
     except etree.ParseError:
         wrapped = "<div>%s</div>" % encode(value)
-        root = etree.fromstring(wrapped, etree.HTMLParser())
+        root = etree.fromstring(wrapped, etree.HTMLParser(encoding='utf-8'))
         # html > body > div
         trans.process(root[0][0])
         return trans.get_done()[5:-6]