Moving UpperTriangular matrix to mahout.math; adding DenseSymmetric matrix.
Adding test for dense symmetric matrix asserting Eigen decomposition equivalent to that over a dense matrix.
Switching SSVD uses to UpperTriangular.
Bug fixes in constructor-by-vector
Switching distributed SSVD to use EigenDecomposition. Reversing sort procedure for EigenDecomposition.
Fixing Lanczos for the correct order coming out of eigen dec
Adding optimized left and right multiplications to the diagonal matrix.
Merge remote-tracking branch 'mahout-commits/MAHOUT-1281' into dev-0.9.x-scala

Conflicts:
Merge remote-tracking branch 'mahout-commits/MAHOUT-1282' into dev-0.9.x-scala
elementwise matrix and vector ops (again!)