DB changes:
- Added idpadre in categories (so we can manage sub-categories)
- Removed idfondatore from groups
- Added flags to users_group: attivo, fondatore and contabile
- Added codices field to prodotti
DB Changes:
- Added num_members field to user table
- Removed useless key idug from users_group, now use the iduser-idgroup
Added flags to users_group (attivo, fondatore, contabile)
Added num_members to users