post_notification_emails
========================
id: The email ID 	
email_addr: The email address
gets_mail: //Note: Probably should be boolean by now.
	0 Doesn't get mails
	1 Gets mails
last_modified: The date when the profile has be modified the last time
date_subscribed: The date the user subscribed
act_code: The current activation code
subscribe_ip: The IP from which the user subsribed
format:
	0: Text mail
	1: HTML mail
send_type:
	0: imedeately
	1: dayly
	2: weekly
send_datum: Offset in secounds - Only valid if send_type is 1 or 2
			0 = Sunday 0:00


post_notification_post
======================
post_id: The id of the post
notification_sent: Whether the post has been added to the send queue
	0: Not sent yet
	-1: do not send
	1: Post has been added to the queue
date_saved: The last time the post has been saved	


post_notification_subs
======================

Manage the subscriptions.

email_id:  The Email which subscribe
obj_id:    What has been subscribed to
obj_type:
	0: Posts of a category; id: cat
	1: Comments of a category; id: cat
	2: Comments of a post; id:post

post_notification_queue
=======================

eamil_id:	The Email to send the mail to
obj_id:		The Object to send
state:	The state the mail is in
	0: Unsent
	1: Sent
	-1: Error
	
type:	The type of mail to send
	0: a post
	1: a comment
	2: a Login-Link