Add a dedicated scale and crop method/option

This emulates the image style in Drupal known as "Scale and Crop" with the "allow auto-scaling" option enabled. This will create an image of the exact dimensions required. It uses the resize method with a master value of Inverse and then crops down to the dimensions. Crop's default method automatically centers your crop for you so you end up with a thumbnail of exactly "100x100" (for example) centered on the original image. 

Great for creating image galleries, slideshows, etc.