src/*.c: New format specifiers for psf_binheader_writef

src/*.c: New format specifiers for psf_binheader_writef

There was a long standing problem where the compiler was not able to
check format speficiers for `psf_binheader_writef`. This is a standard
problem with using non-standard format specifiers with stdargs.

This solution wraps all non-format parameters pass to that functions
with a macro which performs an explicit type cast. The second step is
to have a Python program make sure these macro wrappers match the
format specifiers.

Change-Id: I8bc65d9671c98d11f87e07979372877f4e9ff048
Closes: https://github.com/erikd/libsndfile/issues/241