[bugfix] Fix thumbnails not taking exif rotation into account (#746)

* use disintegration/imaging instead of nfnt/resize

* update tests

* use disintegration lib for thumbing (if necessary)

vendor/golang.org/x/image/tiff/fuzz.go

@@ -0,0 +1,29 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build gofuzz
+
+package tiff
+
+import "bytes"
+
+func Fuzz(data []byte) int {
+	cfg, err := DecodeConfig(bytes.NewReader(data))
+	if err != nil {
+		return 0
+	}
+	if cfg.Width*cfg.Height > 1e6 {
+		return 0
+	}
+	img, err := Decode(bytes.NewReader(data))
+	if err != nil {
+		return 0
+	}
+	var w bytes.Buffer
+	err = Encode(&w, img, nil)
+	if err != nil {
+		panic(err)
+	}
+	return 1
+}