Prevent searching or waiting next to a hostile

Generally speaking there's no reason to wait or search next to
a hostile monster, so let's just prevent those actions. You can
still do those commands by prefixing them with the 'm' prefix.

src/cmd.c

@@ -2995,6 +2995,8 @@ int NDECL((*cmd_func));
         || cmd_func == doloot
         /* travel: pop up a menu of interesting targets in view */
         || cmd_func == dotravel
+        /* wait and search: allow even if next to a hostile monster */
+        || cmd_func == donull || cmd_func == dosearch
         /* wizard mode ^V and ^T */
         || cmd_func == wiz_level_tele || cmd_func == dotelecmd
         /* 'm' prefix allowed for some extended commands */

src/detect.c

@@ -1782,6 +1782,10 @@ register int aflag; /* intrinsic autosearch vs explicit searching */
 int
 dosearch()
 {
+    if (!iflags.menu_requested && !g.multi && monster_nearby()) {
+        Norep("You already found a monster.");
+        return 0;
+    }
     return dosearch0(0);
 }
 

src/do.c

@@ -1970,6 +1970,11 @@ long timeout UNUSED;
 int
 donull()
 {
+    if (!iflags.menu_requested && !g.multi && monster_nearby()) {
+        Norep("Are you waiting to get hit?");
+        return 0;
+    }
+
     return 1; /* Do nothing, but let other things happen */
 }