Found potential mistake in SpMV/spmv.h where MatrixReader doesn't need to be called twice. Commiting to show in meeting.

Implemented rough version of result comparison. Implemented benchmark for comparison of TNL CSR and Cusparse on GPU. Edited log file formatting.

Implemented for the benchmark to write the output of MatrixReader into the log file. BUG: Every other error message added into the Benchmark doesn't have a '!' as a prefix in the log file.

Changed TYPED_TEST_CASE to TYPED_TEST_SUITE, as per google test recommendation which said that TYPED_TEST_CASE is deprecated.

Copied tnl-benchmark-spmv files and spmv.h from BLAS to SpMV. Deleted min/max size and stepFactor. Not working yet, backup purposes.

Refactoring for execution policies

Closes #49, #46, and #11

See merge request !42

Closes #49

They are not suitable for more than 2 devices/execution types; their design
breaks the Open-Closed Principle. Instead, a type template "Self" was
created, which allows to change any template parameter.

Serialization in TNL::File: File::save and File::load are specialized by Allocator instead of Device

The usage of algorithms such as MemoryOperations or Reduction is not
bound to a particular container. On the other hand, ArrayIO,
ArrayAssignment, VectorAssignment and StaticArrayAssignment are just
implementation details for the containers - moved into
TNL/Containers/detail/

Also moved ParallelFor, StaticFor, StaticVectorFor, TemplateStaticFor
into TNL/Algorithms/