p2p: improve read deadlines

There are now two deadlines, frameReadTimeout and payloadReadTimeout.

The frame timeout is longer and allows for connections that are idle.
The message timeout is still short and ensures that we don't get stuck
in the middle of a message.

p2p/peer.go

@@ -15,22 +15,12 @@ import (
 	"github.com/ethereum/go-ethereum/rlp"
 )
 
-const (
-	// maximum amount of time allowed for reading a message
-	msgReadTimeout = 5 * time.Second
-	// maximum amount of time allowed for writing a message
-	msgWriteTimeout = 5 * time.Second
-	// messages smaller than this many bytes will be read at
-	// once before passing them to a protocol.
-	wholePayloadSize = 64 * 1024
-
-	disconnectGracePeriod = 2 * time.Second
-)
-
 const (
 	baseProtocolVersion    = 2
 	baseProtocolLength     = uint64(16)
 	baseProtocolMaxMsgSize = 10 * 1024 * 1024
+
+	disconnectGracePeriod = 2 * time.Second
 )
 
 const (