[IMP] add security to account.voucher model

[Ariel E. Figueroa - http://www.humanytek.com]

Hi team:

Please add a new security group related with the model account.voucher, the group must be called "Ver pagos" (see payments), if the user has the group un state "True" the user can be see all the payments, if not, the user only can see its own payments.

Thanks!

[Ariel E. Figueroa - http://www.humanytek.com (arielfigue)]

Done!