I planned to put just the file system routines into these files, but
there are starting to be so many of them that I don't want to
duplicate the same set for networking, subprocesses etc.
Apparently in addition to "float", "double" and "long double" there
are now standard types in <math.h> called "float_t" and "double_t".
Those types don't need to be equivalent to "float" and "double". Gah!