[FIX] website_sale: no need to specific to a selection field that it is of type char

Besides, if set, the field will appear as a simple char field in the form view & editable lists
+ADD the type in the editable view
[FIX] website: use dom element instead of jquery class to click input file

For some reasons, the browser will prevent to open the system file browser when clicking the input file with javascript using the jquery class element, but it works when using the standard js dom element.
Merge branch '8.0' of https://github.com/odoo/odoo into 8.0-win32