Reimplemented Config::ConfigDescription and Config::ParameterContainer using std::vector instead of TNL::List

This is much safer and simpler because it solves many problems due to
cyclic inclusion of TNL headers.

Having 4 different files (Cuda.h, Cuda_impl.h, Cuda.cpp, Cuda.cu) for
one class is not clear at all. On a related note, a class with 28
methods is clearly too long to be considered as well-designed, so it
should be split into several subclasses. Obviously, the full CUDA
support cannot be provided/wrapped by a single class so the design
should be more flexible.

This will fix the bugs described in the FIXME notes.

Compilation fails due to cyclic dependency between the headers, it will
be fixed later.

Fortunately it's not used anywhere at the moment...

This is necessary if the pointer type is const-qualified.