only add golang.org vendor

vendor/github.com/siddontang/go/hack/hack.go

@@ -1,27 +0,0 @@
-package hack
-
-import (
-	"reflect"
-	"unsafe"
-)
-
-// no copy to change slice to string
-// use your own risk
-func String(b []byte) (s string) {
-	pbytes := (*reflect.SliceHeader)(unsafe.Pointer(&b))
-	pstring := (*reflect.StringHeader)(unsafe.Pointer(&s))
-	pstring.Data = pbytes.Data
-	pstring.Len = pbytes.Len
-	return
-}
-
-// no copy to change string to slice
-// use your own risk
-func Slice(s string) (b []byte) {
-	pbytes := (*reflect.SliceHeader)(unsafe.Pointer(&b))
-	pstring := (*reflect.StringHeader)(unsafe.Pointer(&s))
-	pbytes.Data = pstring.Data
-	pbytes.Len = pstring.Len
-	pbytes.Cap = pstring.Len
-	return
-}