finish deprecating eval closures

finish deprecating eval closures

* libguile/deprecated.h:
* libguile/deprecated.c (scm_eval_closure_lookup)
  (scm_standard_eval_closure, scm_standard_interface_eval_closure)
  (scm_eval_closure_module): Deprecate these, as they are unused.

* libguile/modules.h:
* libguile/modules.c: Remove deprecated code.

* module/oop/goops/util.scm (top-level-env, top-level-env?): Deprecate.

* module/ice-9/deprecated.scm (set-system-module!): Deprecate.
  (module-eval-closure): Deprecate, by overriding the core definition to
  return a fresh eval closure.

* module/ice-9/boot-9.scm (make-module): Don't set an eval closure on
  the module.
  (the-root-module, the-scm-module): Don't call set-system-module!.