New high resolution grid with heights (heightmap)

This change introduces a new high resolution grid in the ROO files.

* The roomeditor was updated to create this new grid. It will write V13 files now.
* All .ROO files were updated to contain this new grid.
* The new grid has 4 rows per big row, 4 cols per big col (= 16 squares per big square). It's resolution therefore is between the "square" and the "finesquare". A "highresolution" row still has 16 fine-rows.
* The new grid has 4-Bytes (32-Bit) per square. Their usage is:...