LR 4.1 release

I did found the new release (4.0) slower than the 3.X, but it is more complex and a first version of a major release. Anyway, on a quite old notebook, it managed quite well my 80k+ pics archive.

The 4.1 release maybe is not yet as fast as 3.X, but it is quite faster than the 4.0.

Obviously, I'll have to plan a hardware upgrade this year, but the 4.1 made it not so urgent as it was with 4.0