Download a file with the file name from filename attribute field
Same feature as GTK client, to do at SAO [1]
[1] http://doc.tryton.org/4.0/trytond/doc/ref/models/fields.html#trytond.model.fields.Binary.filename
Same feature as GTK client, to do at SAO [1]
[1] http://doc.tryton.org/4.0/trytond/doc/ref/models/fields.html#trytond.model.fields.Binary.filename