Add grid/checkerboard operations with floating point coordinates, or upgrade the current ones
@ell
Submitted by Ell Link to original bug (#764249)
Description
As discussed on IRC, this is a new version of the grid and checkerboard operations, that supports floating point coordinates for all spatial properties.
These are preliminary patches for review. Currently the operations are named "grid2" and "checkerboard2", until we decide how we want to handle them, support a "hidden" ui_meta in GIMP, etc...
Version: git master