Update 1/8/2014

In afxmit/, the files af.h and gccxmit should be replaced by the files
of the same name in this archive.

In afrecv/, the files af.h and  gccrecv should be replaced with the versions
in this archive.

Note that afxmit.c and afrecv.cpp are unchanged.

The changes allow compilation with the -std=c99 option of gcc, which resolves
a number of errors that may result when compiling with your system's default
gcc settings.

Note that af.h is the same in afxmit/ and afrecv/.
