Add posting cooldown

If a user tries to post more than once in a certain amount of time, they
will be blocked from doing so until their cooldown is over. This
required a little bit of hacking to get the board and IP address set
*before* the validation checks were made, but it all appears to work.

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

board/forms.py

@@ -0,0 +1,37 @@
+from django.forms import ModelForm
+from board.models import Post
+
+
+class PostForm(ModelForm):
+    """
+    A form used for new threads for posts.
+
+    This requires the board and the IP address to be specified.
+    """
+
+    class Meta:
+        model = Post
+        fields = ["subject", "name", "text", "image"]
+
+    def __init__(self, *args, board, ip, **kwargs):
+        super(PostForm, self).__init__(*args, **kwargs)
+        self.instance.board = board
+        self.instance.ip = ip
+
+
+class ReplyForm(PostForm):
+    """
+    A form used for replies to posts.
+
+    This requires the OP post, the reply post, the board, and the IP address be
+    specified.
+    """
+
+    class Meta:
+        model = Post
+        fields = ["name", "text", "image"]
+
+    def __init__(self, *args, op, reply, **kwargs):
+        super(ReplyForm, self).__init__(*args, **kwargs)
+        self.instance.op = op
+        self.instance.reply = reply