use gnulib's progname module

use gnulib's progname module

* bootstrap.conf (gnulib_modules): Add progname.
* debug/clearfat/clearfat.c: Include "progname.h".
(main): Call set_program_name rather than setting program_name.
* parted/parted.c: Likewise.
* partprobe/partprobe.c: Likewise.
* libparted/tests/disk.c: Include "progname.h" and call
set_program_name even though program_name isn't used, yet.
* libparted/tests/label.c: Likewise.