Batch option: Image tiling

[FireSnow]

Please add a new batch processing option - image tiling. This can be implemented as a separate action or as a part of canvas resize action.

Currently you have 2 options of canvas resize: filling the added space with background color or with pixel color. Image tiling can be a third option - to fill the space with the same image, multiplicatively tiled around.

Alternatively, as a separate action, the image tiling can have an option of specifying the number of horizontal and vertical rows in the resulting image.