compress unscaled when original is active

[tijmenbruggeman]

WordPress scales down the original image when big_image_size_threshold is hit (defaults to 2560px). The scaled down version will be used when a user requests the full image and generates thumbnails using the unscaled version.

Users wanted to compress the unscaled original image as well as these might take up a lot of disk space.

Changes

• src/class-tiny-image.php when original image exists, will also add a Tiny_Image_Size for the unscaled version;
• get_active_tinify_sizes will return the unscaled size when original is enabled;
• src/class-tiny-settings.php will preserve meta data on the unscaled version if enabled;

Considerations

• When the original is enabled, it will now count as two compressions as the unscaled version will also account for one. I thought it was better to give an estimate to be on the safe side.