EclipseWriter: support reordering of compressed cells.

This commit removes the implicit assumption that the cells are ordered following the Eclipse Cartesian logic 
( e.g. as made sure by this two assertions:
assert(compressedToCartesianCellIdx[i] >= i);
assert(i == 0 || compressedToCartesianCellIdx[i - 1] < compressedToCartesianCellIdx[i]);
)
Now arbitrary cell orders are possible and data is remapped to the Eclipse order upon write. 
Actually you questions also applies to one of the restrictToActiveCells methods. Two is one to many I guess.