Moved all backend *.h files into the SOURCES primary as Automake
documentation states all source file types should be listed. This
causes Automake to include *.h files in rebuild rules for the targets.
Removed the '-DIN_HAMLIB' assignment from the CFLAGS primary in each
backend and assigned it to AM_CPPFLAGS in configure.ac. The effect is
the same and it simplifies the backend Makefile.am files.
Removed all commented lines.
Nate Bargmann