The following modules must be implemented:
 tg.copy -- to copy raster table entries + time + metadata
 tg.rename -- rename existing raster table entries + metadata + time
 t.info -- infos about temporal raster maps
 t.create -- to create temporal raster maps
 t.register -- register raster maps in the temporal datatypeas (temporal raster map)
 t.unregister -- unregister raster maps from temporal datatypes (temporal raster map)

See also: lib/TODO
          sql/TODO