- Removed differences between MAKE/OPTIONS/Makefile.intel_cpu/coprocessor and
  CMake compilation and added INTEL_ARCH to select between CPU and KNL.
- Added some sanity checks for requirements
- Added FindTBB

The upper or lowercase matters. It won't work with lower case.

this changes the CMake configuration file.
also, the special case of Windows not supporting posix_memalign() is documented.
some more explanations for FFTs and memory alignment are added

It should not be its own chapter. The intro seems to be the right place for it.