Error rewrites (#43)

* pcap: reuse Frame memory

* slog: reduce heap allocations of addresses; also prevent heap alloc of dhcp options in pcap

* dns: heapless improvement; add StackAsync buffer for more heapless operation; start thinking of errors

* errors: begin standardise errors in lneto

* errors: finish standardization of errors

* fix merge issues

* add more lneto errors to rest of package

* format errors.go

internet/definitions.go

@@ -93,7 +93,7 @@ func (h *handlers) prepAdd() error {
 	if h.full() {
 		h.compact()
 		if h.full() {
-			return errNodesFull
+			return lneto.ErrBufferFull
 		}
 	}
 	return nil
@@ -200,11 +200,7 @@ func (h *handlers) encapsulateAny(buf []byte, offsetIP, offsetThisFrame int) (_
 }
 
 var (
-	errZeroMaxNodesArg = errors.New("zero max nodes arg")
-	errZeroPort        = errors.New("port must be greater than zero")
-	errInvalidProto    = errors.New("invalid protocol")
 	errProtoRegistered = errors.New("protocol already registered")
-	errNodesFull       = errors.New("no more room for new nodes")
 	_                  = net.ErrClosed
 )