Given everything from lapply, combine it.
combine_output(tile_output, blocksize, only_name = NULL)
| tile_output | is a list where each entry is a all data for a single
tile. Each entry has one member named   | 
    
|---|---|
| blocksize | An named array with "row" and "col".  | 
    
| only_name | The name of a single array to combine from all tiles.  | 
    
The data combined, where each piece is offset by the same offset.