Implement payment backends and interaction

Advances #3 (closed)

aleksis/apps/tezor/rules.py

@@ -80,7 +80,7 @@ change_payment_variant_predicate = has_person & is_in_payment_status(PaymentStat
 rules.add_perm("tezor.change_payment_variant", change_payment_variant_predicate)
 
 # Start payment
-do_payment_predicate = has_person & (is_in_payment_status(PaymentStatus.WAITING) | is_in_payment_status(PaymentStatus.INPUT)) & ((is_own_invoice | is_site_preference_set("payments", "public_payments")) | has_global_perm("tezor.do_payment") | has_object_perm("tezor.do_payment"))
+do_payment_predicate = has_person & (is_in_payment_status(PaymentStatus.WAITING) | is_in_payment_status(PaymentStatus.INPUT) | is_in_payment_status(PaymentStatus.ERROR) | is_in_payment_status(PaymentStatus.REJECTED)) & ((is_own_invoice | is_site_preference_set("payments", "public_payments")) | has_global_perm("tezor.do_payment") | has_object_perm("tezor.do_payment"))
 rules.add_perm("tezor.do_payment", do_payment_predicate)
 
 # View invoice