v5.5.1alpha
lib: Update Makefile.am for new header files.
lib: Add getopt-cdefs.h for getopt_long update.
lib: Copy new header files from Gnulib without modification.
lib: Silence -Wsign-conversion in getopt.c.
lib: Update getopt.in.h from Gnulib with modifications.
lib: Update getopt1.c from Gnulib.
lib: Update getopt_int.h from Gnulib.