Merge branch 'develop' into namespaces

Conflicts:
	src/TNL/CMakeLists.txt
	src/TNL/Devices/Cuda.cpp
	src/TNL/Meshes/GridDetails/GridTraverser_impl.h
	src/TNL/Problems/HeatEquationProblem.h
	src/TNL/Solvers/ODE/ExplicitSolver.h
	src/TNL/TimerCPU.h
	src/TNL/TimerRT.h