Users may only report a post once per IP address.

If a user *really* doesn't like a post, they may try to report it
multiple times. Users may now only report a single post once per IP
address.

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

board/forms.py

@@ -101,6 +101,8 @@ class ReportForm(ModelForm):
                 record = ReportRecord.objects.get(post=self.op)
             except ReportRecord.DoesNotExist:
                 record = ReportRecord.objects.create(post=self.op)
+        if record.report_set.filter(ip=self.instance.ip):
+            raise ValidationError(_("You have already reported this post."))
         self.instance.record = record
         return super(ReportForm, self).clean()