Fix reference to README file
(compose_directed_moves): Speedup: Fix test whether result is empty
(reduce_with_dense_moves): Speedup: Bail out early if there are no dense moves
(reduce_with_dense_moves): Speedup: Bail out early if nothing needs to be reduced
(is_QQ_linearly_independent): Speedup: Use faster way to get coordinates
Speedup: Cache the hash value of RealNumberFieldElements
(is_QQ_linearly_independent): Speedup when all numbers are from the same number field already
Don't show discontinuity markers in moves diagrams