Update to Newmat11
Contributed by Kamel Derouiche via PR pkg/43741

Changes in this version:

It works with Borland Builder version 6, 8;
Microsoft Visual C++ 6,7,8; Open Watcom 1.7a;
Gnu version 3, 4 and Intel for Windows & Linux compilers 9, 10.

Options and work-arounds for older compilers are being removed.

You can enter values from an integer array with statements like

  Matrix A(3,2); int a[] = { 11,12,21,22,31,33 };  A << a;

There is a new matrix type SquareMatrix. You can use this where
you know a matrix is square. The only place where the information
that a matrix is used is in the Kronecker product KP(A,B).
If A is band and B is any square matrix type (i.e. type SquareMatrix
or band, triangular, symmetric or diagonal) the result is band.
If B is type Matrix then the result is of type Matrix.
Apart from this it may be worth using the SquareMatrix type to
improve readability of a program and to make sure that a matrix
that is intended to be square really is square.

There is a new routine for carrying out cross products of
ColumnVectors or RowVectors of length 3 and new routines for
updating a triangular matrix derived from a Cholesky decomposition.

Interfacing with old C functions involving one and two
dimensional arrays is simplified.

Additional QR functions, extend_orthogonal function.

Lower-case versions of functions.

You can use the manipulators scientific and fixed in the matrix
output expressions.

(asau)