intCoord: Remove unnecessary assertions
TileCombiner: Group tiles in output file together as objects

Tiles have names. The name is the number of tiles output before the current
one by default. It can be overridden by user calling `addTile`.
TileCombiner: Separate in a dedicated script
GetData: Enable outside "__main__" script
saveRoi, intCoord, tile_size_*: Separate in dedicated script "save_roi.py"
saveRoi: Rename to save_roi