add inline editing for mail address targets

- move active flag into managemails.models.ActivateAbleMixin
- refactor Mailbox and Mailaddress to use ActivateAbleMixin
- implement managemails.models.Mailbox.__str__
- add managemails.admin.ActivationChangeMixin to provide activate and
  deactivate actions for model admin classes
- add activate and deactivate actions for managemails.admin.MailboxAdmin
- add managemails.admin.MailAddressAdmin and inlines for MailAddressMailbox and
  MailAddressForward management on the MailAddress management admin page

gnuviechadmin/managemails/models.py

@@ -16,13 +16,24 @@ class MailDomain(models.Model):
         return self.domain
 
 
-class Mailbox(models.Model):
+class ActivateAbleMixin(models.Model):
+    """
+    Mixin for model classes that can be active or inactive.
+
+    """
+    active = models.BooleanField(default=True)
+
+    class Meta:
+        abstract = True
+
+
+@python_2_unicode_compatible
+class Mailbox(ActivateAbleMixin, models.Model):
     username = models.CharField(max_length=128, unique=True)
     password = models.CharField(max_length=255)
     home = models.CharField(max_length=255)
     uid = models.PositiveSmallIntegerField()
     gid = models.PositiveSmallIntegerField()
-    active = models.BooleanField(default=True)
 
     class Meta:
         verbose_name = _('Mailbox')
@@ -31,12 +42,14 @@ class Mailbox(models.Model):
     def set_password(self, password):
         self.password = sha512_crypt.encrypt(password)
 
+    def __str__(self):
+        return self.username
+
 
 @python_2_unicode_compatible
-class MailAddress(models.Model):
+class MailAddress(ActivateAbleMixin, models.Model):
     localpart = models.CharField(max_length=128)
     domain = models.ForeignKey(MailDomain)
-    active = models.BooleanField(default=True)
 
     class Meta:
         unique_together = ('localpart', 'domain')