Adds the database for checking new channels/items.

In this iteration the key passed to the database is the Title which is
obviously silly.
I'm still looking for a configurable way of generating the unique key.

feed.go

@@ -58,6 +58,9 @@ type Feed struct {
 	// Url from which this feed was created.
 	Url string
 
+	// Database containing a list of known Items and Channels for this instance
+	database *database
+
 	// A notification function, used to notify the host when a new channel
 	// has been found.
 	chanhandler ChannelHandler
@@ -76,6 +79,7 @@ func New(cachetimeout int, enforcecachelimit bool, ch ChannelHandler, ih ItemHan
 	v.CacheTimeout = cachetimeout
 	v.EnforceCacheLimit = enforcecachelimit
 	v.Type = "none"
+	v.database = NewDatabase()
 	v.chanhandler = ch
 	v.itemhandler = ih
 	return v
@@ -159,9 +163,34 @@ func (this *Feed) makeFeed(doc *xmlx.Document) (err error) {
 		this.CacheTimeout = this.Channels[0].TTL
 	}
 
+	this.notifyListeners()
+
 	return
 }
 
+func (this *Feed) notifyListeners() {
+	var newchannels []*Channel
+	for _, channel := range this.Channels {
+		if this.database.request <- channel.Title; <-this.database.response {
+			newchannels = append(newchannels, channel)
+		}
+
+		var newitems []*Item
+		for _, item := range channel.Items {
+			if this.database.request <- item.Title; <-this.database.response {
+				newitems = append(newitems, item)
+			}
+		}
+		if len(newitems) > 0 {
+			this.itemhandler(this, channel, newitems)
+		}
+	}
+
+	if len(newchannels) > 0 {
+		this.chanhandler(this, newchannels)
+	}
+}
+
 // This function returns true or false, depending on whether the CacheTimeout
 // value has expired or not. Additionally, it will ensure that we adhere to the
 // RSS spec's SkipDays and SkipHours values (if Feed.EnforceCacheLimit is set to