Re-factor payment methods and move configuration to the database

This is a major refactoring of how the payment method integrates, with
the intetion of making it more flexible and more easy to use.

1. Configuration now lives in the database instead of local_settings.py.
2. This configuration is edited through the /admin/ interface, which
   makes it a lot easier to add constraints (and instructions), thus
    preventing misconfiguration.
3. Invoice payment methods are now separate from invoice payment
   implementations. That means there can be multiple instances of the
   same payment method, such as multiple different paypal accounts,
   being managed.
4. All payment method implementations are now available in all
   installations, including Braintree and Trustly. This retires the
   x_ENABLED settings in local_settings.py. The code won't actually run
   unless there are any payment methods defined with them.
5. On migration, all payment methods that are marked as inactive and
   have never been used are removed. Any payment method that has been
   used is left around, since there are old invoices connected to it.
   Likewise, any payment method that is selected as available for any
   sponsorship level (past or future) is left in the system.

XXXXXX manual action needed on production systems XXXXXX

1. Settings for payment methods should be migrated automatically, but
   should of course be verified!
2. The template for Manual Bank Transfer is *not* migrated, since it
   wasn't in settings.py, but in a template and overriden downstream.
   Migrate the contents of the template invoices/banktransfer.html to the
   database using the /admin/ interface. When this is done, the template
   can be removed.
3. Notification URLs in Adyen must be updated in the Adyen backoffice to
   include the payment method id in the url (adding a /n/ to the end of the
   URL, with n being the id of the payment method).
4. Notification URLs in Paypal must be updated the same way.

1 files changed, 3 insertions, 4 deletions

diff --git a/postgresqleu/paypal/admin.py b/postgresqleu/paypal/admin.py
index c2334cff..a5d9c5fa 100644
--- a/postgresqleu/paypal/admin.py
+++ b/postgresqleu/paypal/admin.py
@@ -1,10 +1,10 @@
 from django.contrib import admin
-from .models import SourceAccount, TransactionInfo, ErrorLog
+from .models import TransactionInfo, ErrorLog
 
 
 class TransactionInfoAdmin(admin.ModelAdmin):
-    list_display = ('timestamp', 'sourceaccount', 'sender', 'amount', 'fee', 'transtext', 'matched', )
-    list_filter = ('sourceaccount', 'matched', )
+    list_display = ('timestamp', 'sender', 'amount', 'fee', 'transtext', 'matched', )
+    list_filter = ('matched', )
     ordering = ('-timestamp', )
     search_fields = ('paypaltransid', 'sender', 'sendername', 'transtext',)
 
@@ -15,6 +15,5 @@ class ErrorLogAdmin(admin.ModelAdmin):
     ordering = ('-timestamp', )
 
 
-admin.site.register(SourceAccount)
 admin.site.register(TransactionInfo, TransactionInfoAdmin)
 admin.site.register(ErrorLog, ErrorLogAdmin)