[SYSTEMDS-2641] New slice finding algorithm (dml implementation)
[SYSTEMDS-2641] New slice finding algorithm (dml implementation)

This patch adds the new slice finding implementation via linear algebra
(SliceLine). Even without full pruning, this implementation performs
exact slice finding for the Salaries dataset in 2.6s (incl compilation
and startup).

apache/incubator-systemml,apache/incubator-systemml,apache/incubator-systemml,apache/incubator-systemml,apache/incubator-systemml,apache/incubator-systemml