This adds copyright/license notification blocks CMake's non-find
modules. Most of the modules had no notices at all. Some had notices
referring to the BSD license already. This commit normalizes existing
notices and adds missing notices.
This stores CMAKE_Fortran_COMPILER_SUPPORTS_F90 in the Fortran compiler
information file CMakeFiles/CMakeFortranCompiler.cmake instead of in
CMakeCache.txt. This file makes the result available to try-compile
projects.