Display Condition type in list views

* Whether a Flag is disable-if-false or enable-if-true is a very
  important detail
* But one that's easy to get wrong
* And it's hard to spot problems without inspecting every single flag

This change adds the Condition into the various admin list views, so
that it's easier to scan them all for problems and look for inconsistencies.

vendor/registrasion/registrasion/admin.py

@@ -143,6 +143,11 @@ class VoucherAdmin(nested_admin.NestedAdmin):
         ''' List the effects of the voucher in the admin. '''
         out = []
 
+        try:
+            voucher_condition = obj.voucherflag.condition
+        except ObjectDoesNotExist:
+            voucher_condition = None
+
         try:
             discount_effects = obj.voucherdiscount.effects()
         except ObjectDoesNotExist:
@@ -155,6 +160,8 @@ class VoucherAdmin(nested_admin.NestedAdmin):
 
         if discount_effects:
             out.append("Discounts: " + str(list(discount_effects)))
+        if voucher_condition:
+            out.append("Condition: " + obj.voucherflag.get_condition_display())
         if enabling_effects:
             out.append("Enables: " + str(list(enabling_effects)))
 
@@ -181,7 +188,7 @@ class ProductFlagAdmin(
     fields = ("description", "enabling_products", "condition", "products",
               "categories"),
 
-    list_display = ("description", "enablers", "effects")
+    list_display = ("description", "condition", "enablers", "effects")
 
 
 # Enabling conditions
@@ -194,7 +201,7 @@ class CategoryFlagAdmin(
     fields = ("description", "enabling_category", "condition", "products",
               "categories"),
 
-    list_display = ("description", "enabling_category", "effects")
+    list_display = ("description", "condition", "enabling_category", "effects")
     ordering = ("enabling_category",)
 
 
@@ -215,13 +222,14 @@ class GroupMemberFlagAdmin(admin.ModelAdmin, EffectsDisplayMixin):
 
     fields = ("description", "group", "products", "categories")
 
-    list_display = ("description", "effects")
+    list_display = ("description", "condition", "effects")
 
 
 @admin.register(conditions.TimeOrStockLimitFlag)
 class TimeOrStockLimitFlagAdmin(admin.ModelAdmin, EffectsDisplayMixin):
     list_display = (
         "description",
+        "condition",
         "start_time",
         "end_time",
         "limit",