[6.0RC1] documents - separation per company

invalid, keep the url simple, and possible in the configuration

I checked now with cadaver (on linux) and get the same result - hence the web_dav module does not work correctly

sorry wrong bug

@tft
Invoice report (account/report/account_print_invoice.rml) uses
(object.state in ('open','paid')) and ('INV'+(object.number or '').replace('/',''))
as default name to create attachments, regardless from which company in the db

to get a unique name it is neccessary to include the company_id.name in the attachment naming

(object.state in ('open','paid')) and ('INV-'+(object.company_id and (object.company_id.name+'-'))+(object.number or '').replace('/','-'))

save as attachment prefix field is to short !!!! to enter this string

had to increase the length of the field to 256
        'attachment': fields.char('Save As Attachment Prefix', size=256, help='This is the filename of the attachment used to store the printing result. Keep empty to not save the printed reports. You can use a python expression with the object and time variables.'),

obviously it is also possible (a must !) to create a folder per company manually to keep documents separated by company