Tue 29 Jun 2021 : extended dbl_linearization with matrix versions,
  tested by test_dbl_linearization.  Added the linearized versions of the
  upper triangular solvers to dbl_matrices_host, with added tests in
  test_matrices_testers.cpp.  Updated makefile_unix and makefile_windows.

Mon 28 Jun 2021 : updated random_matrices with new versions of functions to
  generate random matrices based on the log(1+x) expansion.
  Add dbl_linearization and test_dbl_linearization, updated makefiles;
  added function to random_matrices to make random complex vectors.

Fri 25 Jun 2021 : added prompt for verbose level in dbl_vectors_testers.cpp,
  with a sum of errors computation on the inner products.
  Extended dbl_matrices_kernels with complex versions of the matrix-vector
  products, tested by dbl_vectors_testers.cpp.
  Added the log2(#cols) summation kernels to dbl_matrices_kernels.cu,
  with an update in dbl_vectors_testers.cpp.

Thu 24 Jun 2021 : fixed bug in the convolutions kernel of 
  dbl_matrices_kernels.cu, tested by dbl_vectors_testers.cpp.
  Added summation to dbl_matrices_kernels, tested by dbl_vectors_testers.cpp,
  okay for dimensions equal to powers of 2.
  Updated dbl_matrices_kernels and dbl_vectors_testers.cpp
  so the sum reduction now works for any dimension.
  Added complex versions to dbl_matrices_kernels, with added tests
  to dbl_vectors_testers.cpp.

Wed 23 Jun 2021 : more uniform and consistent naming of functions
  in dbl_matrices_host, dbl_matrices_kernels, with caused updates
  in dbl_vectors_testers.cpp and dbl_matrices_testers.cpp.

Tue 22 Jun 2021 : new dbl_matrices_kernels with kernels for inner products.
  Updated the makefile_unix and makefile_windows.

Mon 21 Jun 2021 : new dbl_vectors_testers with code from dbl_matrices_testers;
  splitted test_dbl_series_vectors into test_dbl_vectors, test_dbl_matrices.
  Updated all makefiles accordingly.  Shuffled tests in test_dbl_matrices.cpp.
  New test_upper_jobs.cpp, with updated makefiles.

Tue 2 Mar 2021 : added verbose flags in dbl_matrices_host to the lufac
  functions and the solvers.

Sat 27 Feb 2021 : added verbose mode to the forward substitution solvers in
  dbl_matrices_host; and did the same for the backward substitution solvers.

Sat 20 Feb 2021 : to dbl_matrices_host, added forward substitution and
  a function for a LU factorization solver.  Adjusted the forward
  substitution for systems with ones on the diagonal.  Added testers on
  the LU solver in dbl_matrices_testers, updated test_dbl_series_vectors.
  Add functions on complex data to dbl_matrices_{host,testers}, updated
  test_dbl_series_vectors.

Fri 19 Feb 2021 : extended dbl_matrices_host with a matrix-matrix product
  to test the code for the LU factorization in dbl_matrices_testers,
  called in test_dbl_series_vectors.cpp.  Updated makefiles because
  random_numbers are needed to randomize the exp(x) series.

Thu 18 Feb 2021 : added an inplace lu factorization to dbl_matrices_host.

Sun 14 Feb 2021 : added generation of random lower triangular matrices
  to random matrices.

Sat 13 Feb 2021 : to dbl_matrices_host, added an upper triangular solver
  for series with complex coefficients, extended test_dbl_series_vectors.
  Moved functions from test_dbl_series_vectors into dbl_matrices_testers.

Fri 12 Feb 2021 : added an upper triangular solver to dbl_matrices_host,
  tested by test_dbl_series_vectors.

Thu 11 Feb 2021 : extended random_matrices with functions to generate
  upper triangular matrices of random power series.

Wed 10 Feb 2021 : new dbl_matrices_host with code extracted from the
  test_dbl_series_vectors.cpp.

Mon 8 Feb 2021 : extended random_matrices with the generation of complex
  series matrices and test_dbl_series_vectors with a test on the complex
  matrix-vector product.

Sun 7 Feb 2021 : extended random_matrices and test_dbl_series_vectors
  with functions to work with vectors of complex numbered series.

Sat 6 Feb 2021 : extended random_matrices with function to generate
  one random vector and one random matrix.  Added matrix vector products
  and tests in test_dbl_series_vectors.cpp.

Fri 5 Feb 2021 : added the inner product to test_dbl_series_vectors.cpp.

