Extends seeder

Ajout de valeurs dans les seeds, histoire d'avoir des données à tester
Supression doublons acl

suppression des seeds plus nécessaires
changements mineurs
Merge remote-tracking branch 'origin/dev/master' into dev/Robert/tablesperiph
Merge remote-tracking branch 'origin/dev/master' into dev/Robert/tablesperiph
corrections tables et debut tables instruments
Fixe duplicate entry in SkillTableSeeder
Fix on skill migration. name_de is now unique
Modify ImageTableSeeder - added some value in artist_id
added a unique index on locale in language table
added unique indexes

email on users
name on groups
Merge remote-tracking branch 'origin/dev/Robert/tablesperiph' into laravel/migrations/fix
fixed several mistakes

default values
nullable values
unqiue values
fixed conflict