Log Message:
Changes 3.3.1:
* Reduced planning time in estimate mode for sizes with large prime factors.
* Added AVX autodetection under Visual Studio.
* Modern Fortran interface now uses a separate fftw3l.f03 interface file for
  the long double interface, which is not supported by some Fortran compilers.
  Provided new fftw3q.f03 interface file to access the quadruple-precision FFTW
  routines with recent versions of gcc/gfortran.
* Added support for the NEON extensions to the ARM ISA.
* MPI code now compiles even if mpicc is a C++ compiler.