Terminate on interface deletion

Program now terminates when the interface is removed
Increases the number of os threads (relevant for Go <1.5, not tested)
More consistent commenting
Improved logging (additional peer information)

src/ip.go

@@ -5,17 +5,13 @@ import (
 )
 
 const (
-	IPv4version           = 4
 	IPv4offsetTotalLength = 2
 	IPv4offsetSrc         = 12
 	IPv4offsetDst         = IPv4offsetSrc + net.IPv4len
-	IPv4headerSize        = 20
 )
 
 const (
-	IPv6version             = 6
 	IPv6offsetPayloadLength = 4
 	IPv6offsetSrc           = 8
 	IPv6offsetDst           = IPv6offsetSrc + net.IPv6len
-	IPv6headerSize          = 40
 )