Drop all behavior activated by setting CMAKE_BACKWARDS_COMPATIBILITY to
a value lower than 2.4, and generate an error when projects or the user
attempt to do so. In the error suggest using a CMake 2.8.x release.
Teach cmake_minimum_required to warn about projects that do not require
at least CMake 2.4. They are not supported by CMake >= 3.0.
Replace the documentation of CMAKE_BACKWARDS_COMPATIBILITY with a
reference to policy CMP0001.
Lookup the Intel VS plugin version on demand in the VS global generator,
compute the corresponding .vfproj format version number, and memoize it.
Add it as a CMAKE_VS_INTEL_Fortran_PROJECT_VERSION platform definition.