reorganize applet table. Eliminates pointers to names.

Should be a big win for libbusybox. busybox wins too:

   text    data     bss     dec     hex filename
 776524     929    9100  786553   c0079 busybox_old
 775903     929    9100  785932   bfe0c busybox_unstripped

libbb/execable.c

@@ -65,7 +65,7 @@ int exists_execable(const char *filename)
  */
 int bb_execvp(const char *file, char *const argv[])
 {
-	return execvp(find_applet_by_name(file) ? bb_busybox_exec_path : file,
+	return execvp(find_applet_by_name(file) >= 0 ? bb_busybox_exec_path : file,
 					argv);
 }
 #endif