everywhere: add email notifications

api/email.go

@@ -0,0 +1,14 @@
+package main
+
+import (
+	"time"
+)
+
+type email struct {
+	Email                      string
+	UnsubscribeSecretHex       string
+	LastEmailNotificationDate  time.Time
+	PendingEmails              int
+	SendReplyNotifications     bool
+	SendModeratorNotifications bool
+}