more doc comments

exchange/offline/offline.go

-package bitswap
+// package offline implements an object that implements the exchange
+// interface but returns nil values to every request.
+package offline
 
 import (
 	"errors"

exchange/offline/offline_test.go

-package bitswap
+package offline
 
 import (
 	"testing"

net/swarm/swarm.go

+// package swarm implements a connection muxer with a pair of channels
+// to synchronize all network communication.
 package swarm
 
 import (

routing/dht/handlers.go

@@ -12,6 +12,7 @@ import (
 	ds "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-datastore"
 )
 
+// The number of closer peers to send on requests.
 var CloserPeerCount = 4
 
 // dhthandler specifies the signature of functions that handle DHT messages.