remove program-name, program-documentation

remove program-name, program-documentation

* libguile/programs.h:
* libguile/programs.c (scm_program_name): Remove. procedure-name is
  sufficient.

* module/system/vm/program.scm (program-name): Remove from exports list.
  (program-documentation): Remove; procedure-documentation is
  sufficient.

* libguile/debug.c (scm_procedure_name): Remove special case for
  programs.

* module/language/tree-il/analyze.scm (validate-arity): Use
  procedure-name.

* module/ice-9/documentation.scm (object-documentation): Just use
  procedure-documentation, without special cases for programs.