MAINT: print that we are cythonizing

build logs should always give full information on what is being done
Merge pull request #496 from juliantaylor/print-cythonizing

MAINT: print that we are cythonizing
ENH: Add class for reading unformatted Fortran files
Change fortran_file/FortranFile API to match suggestions.

fortran module is now hidden
Corrected tests and doctest