undone the previous change: show_hyps not supported anymore

--- a/src/Pure/proof_general.ML	Tue Sep 20 16:19:51 2005 +0200
+++ b/src/Pure/proof_general.ML	Tue Sep 20 17:01:43 2005 +0200
@@ -565,9 +565,6 @@
      ("show-main-goal",
       ("Show main goal in proof state display",
        bool_option Proof.show_main_goal)),
-     ("show-sort-hypotheses",
-      ("Include sort hypotheses in display of Isabelle theorems",
-       bool_option show_hyps)),
      ("eta-contract",
       ("Print terms eta-contracted",
        bool_option Syntax.eta_contract))]),