Extension:CentralNotice/cn template devices table

Fields
Stores details on all the campaigns known to CentralNotice.

tdev_id
Primary key.

Schema summary
mysql> describe cn_template_devices; +-+-+--+-+-++ +-+-+--+-+-++ +-+-+--+-+-++
 * Field  | Type    | Null | Key | Default | Extra          |
 * tdev_id | int(11) | NO  | PRI | NULL    | auto_increment |
 * tmp_id | int(11) | NO   | MUL | NULL    |                |
 * dev_id | int(11) | NO   |     | NULL    |                |