* [IMP] improve module description
* [IMP] Remove useless comments
* [FIX] Complete incomplete sentence
* [IMP] Replace field 'state' by 'status' in res_partner_id_number
* [IMP] Add new field 'Place of Issuance'
* [FIX] Readme formatting
* [IMP] status is now a selection field
* [IMP] use method to provide the default value for validation_code
* [IMP] Add help texts
* [FIX] Add missing constrains on category_id in res_partner.id_number
The number must be validated also when we change the category