Improve handling of non-square avatars (#7025)

* Crop avatar before resizing (#1268)

Signed-off-by: Rob Watson <rfwatson@users.noreply.github.com>

* Fix spelling error

Signed-off-by: Rob Watson <rfwatson@users.noreply.github.com>

vendor/github.com/oliamb/cutter/README.md

@@ -0,0 +1,107 @@
+Cutter
+======
+
+A Go library to crop images.
+
+[![Build Status](https://travis-ci.org/oliamb/cutter.png?branch=master)](https://travis-ci.org/oliamb/cutter)
+[![GoDoc](https://godoc.org/github.com/oliamb/cutter?status.png)](https://godoc.org/github.com/oliamb/cutter)
+
+Cutter was initially developped to be able
+to crop image resized using github.com/nfnt/resize.
+
+Usage
+-----
+
+Read the doc on https://godoc.org/github.com/oliamb/cutter
+
+Import package with
+
+```go
+import "github.com/oliamb/cutter"
+```
+
+Package cutter provides a function to crop image.
+
+By default, the original image will be cropped at the
+given size from the top left corner.
+
+```go
+croppedImg, err := cutter.Crop(img, cutter.Config{
+  Width:  250,
+  Height: 500,
+})
+```
+
+Most of the time, the cropped image will share some memory
+with the original, so it should be used read only. You must
+ask explicitely for a copy if nedded.
+
+```go
+croppedImg, err := cutter.Crop(img, cutter.Config{
+  Width:  250,
+  Height: 500,
+  Options: cutter.Copy,
+})
+```
+
+It is possible to specify the top left position:
+
+```go
+croppedImg, err := cutter.Crop(img, cutter.Config{
+  Width:  250,
+  Height: 500,
+  Anchor: image.Point{100, 100},
+  Mode:   cutter.TopLeft, // optional, default value
+})
+```
+
+The Anchor property can represents the center of the cropped image
+instead of the top left corner:
+
+```go
+croppedImg, err := cutter.Crop(img, cutter.Config{
+  Width: 250,
+  Height: 500,
+  Mode: cutter.Centered,
+})
+```
+
+The default crop use the specified dimension, but it is possible
+to use Width and Heigth as a ratio instead. In this case,
+the resulting image will be as big as possible to fit the asked ratio
+from the anchor position.
+
+```go
+croppedImg, err := cutter.Crop(baseImage, cutter.Config{
+  Width: 4,
+  Height: 3,
+  Mode: cutter.Centered,
+  Options: cutter.Ratio&cutter.Copy, // Copy is useless here
+})
+```
+
+About resize
+------------
+This lib only manage crop and won't resize image, but it works great in combination with [github.com/nfnt/resize](https://github.com/nfnt/resize)
+
+Contributing
+------------
+I'd love to see your contributions to Cutter. If you'd like to hack on it: 
+
+- fork the project,
+- hack on it,
+- ensure tests pass,
+- make a pull request
+
+If you plan to modify the API, let's disscuss it first.
+
+Licensing
+---------
+MIT License, Please see the file called LICENSE.
+
+Credits
+-------
+Test Picture: Gopher picture from Heidi Schuyt, http://www.flickr.com/photos/hschuyt/7674222278/,
+© copyright Creative Commons(http://creativecommons.org/licenses/by-nc-sa/2.0/)
+
+Thanks to Urturn(http://www.urturn.com) for the time allocated to develop the library.