v0.14.0

• Add ability to extend (pad) the edges of an image.
  #128
  @blowsie

• Add support for Zoomify and Google tile layouts. Breaks existing tile API.
  #223
  @bdunnette

• Improvements to overlayWith: differing sizes/formats, gravity, buffer input.
  #239
  @chrisriley

• Add entropy-based crop strategy to remove least interesting edges.
  #295
  @rightaway

• Expose density metadata; set density of images from vector input.
  #338
  @lookfirst

• Emit post-processing 'info' event for Stream output.
  #367
  @salzhrani

• Ensure output image EXIF Orientation values are within 1-8 range.
  #385
  @jtobinisaniceguy

• Ensure ratios are not swapped when rotating 90/270 and ignoring aspect.
  #387
  @kleisauke

• Remove deprecated style of calling extract API. Breaks calls using positional arguments.
  #276