add model features to hostingpackages

- add properties mailboxes, used_mailbox_count, mailbox_count and
  may_add_mailbox to CustomerHostingPackage class
- use new properties in template dashboard/user_dashboard.html

gnuviechadmin/hostingpackages/models.py

@@ -272,7 +272,12 @@ class CustomerHostingPackage(HostingPackageBase):
         hard = soft * 105 / 100
         return (soft, hard)
 
-    def get_used_mailboxes(self):
+    def get_mailboxes(self):
+        if self.osuser:
+            return Mailbox.objects.filter(osuser=self.osuser).all()
+    mailboxes = property(get_mailboxes)
+
+    def get_used_mailbox_count(self):
         """
         Get the number of used mailboxes for this hosting package.
 
@@ -280,8 +285,9 @@ class CustomerHostingPackage(HostingPackageBase):
         if self.osuser:
             return Mailbox.objects.filter(osuser=self.osuser).count()
         return 0
+    used_mailbox_count = property(get_used_mailbox_count)
 
-    def get_mailboxes(self):
+    def get_mailbox_count(self):
         """
         Get the number of mailboxes provided by this hosting package and all
         of its mailbox options.
@@ -293,6 +299,10 @@ class CustomerHostingPackage(HostingPackageBase):
             mailbox_sum=models.Sum('number')
         )
         return self.mailboxcount + (result['mailbox_sum'] or 0)
+    mailbox_count = property(get_mailbox_count)
+
+    def may_add_mailbox(self):
+        return self.used_mailbox_count < self.mailbox_count
 
     def get_databases(self):
         """