Update for Go 1.3.1

I decided to vendor all debug/dwarf and debug/elf files so that the
project can be go get-table. All changes that I am waiting to land in Go
1.4 are now captured in /vendor/debug/*.

dwarf/line/line_parser_test.go

@@ -16,6 +16,7 @@ func grabDebugLineSection(p string, t *testing.T) []byte {
 	if err != nil {
 		t.Fatal(err)
 	}
+	defer f.Close()
 
 	ef, err := elf.NewFile(f)
 	if err != nil {