Extend & polish compilation fixes for VS 2013.
Workaround for known VS 2013 missing support for defaulted functions.
Do not include mm_malloc.h on MSVC (where it is not available).
Remove the check of positive volume from create_triangulation version with mixed triangulation and cell dimensions.
Fix indentation with AStyle.
CMake: Do not add targets using 'test' command when building for Visual Studio.
Fix compilation of grid_tools for VS 2013.
Fix linking problems with grid_generator for VS 2013.
Take out unnecessary forward declarations from derivative_approximation.h.
Code formatting.
Fix indentation before pull request.