Fixes after merge with 4.1

FOUND is not a reserved keyword anymore
Added Item_field::set_no_const_sub() to be able to mark fields that can't be substituted
Added 'simple_select' method to be able to quickly determinate if a select_result is a normal SELECT
Note that the 5.0 tree is not yet up to date: Sanja will have to fix multi-update-locks for this merge to be complete


BUILD/SETUP.sh:
  Portability fix
client/mysqltest.c:
  Portability fix
mysql-test/r/drop.result:
  updated results
mysql-test/r/func_str.result:
  New warnings (after merge)
mysql-test/r/insert.result:
  Updated tests
mysql-test/r/join_nested.result:
  Updated results (because of new column types in 5.0)
mysql-test/r/lock_multi.result:
  Temporarly wrong results until Sanja fixes multi-update-lock in 5.0
mysql-test/r/multi_update.result:
  Temporary fix until Sanja fixes multi-update locking
mysql-test/r/ps_1general.result:
  Update of results after merge
mysql-test/r/ps_2myisam.result:
  Update of results after merge
mysql-test/r/ps_3innodb.result:
  Update of results after merge
mysql-test/r/ps_4heap.result:
  Update of results after merge
mysql-test/r/ps_5merge.result:
  Update of results after merge
mysql-test/r/ps_6bdb.result:
  Update of results after merge
mysql-test/r/query_cache.result:
  Update of results after merge
mysql-test/r/range.result:
  New results for new tests
mysql-test/r/rpl_auto_increment.result:
  Update with new 4.0 information
mysql-test/r/rpl_charset.result:
  After merge fixes
mysql-test/r/subselect.result:
  After merge fixes
mysql-test/r/view.result:
  Temporary fix until multi-update-locking is fixed
mysql-test/t/drop.test:
  Safety fix
mysql-test/t/multi_update.test:
  Temporary fix until multi-update-locking is fixed
mysql-test/t/rpl_charset.test:
  More comments
mysql-test/t/sp-error.test:
  Updated comments
mysql-test/t/view.test:
  Temporary fix until multi-update-locking is fixed
scripts/mysql_fix_privilege_tables.sh:
  Better error message
sql-common/client.c:
  More debugging
sql/ha_ndbcluster.cc:
  After merge fixes
sql/handler.cc:
  After merge fixes
sql/item.cc:
  Simple optimization of creating item
  After merge fixed
  Added Item_field::set_no_const_sub() to be able to mark fields that can't be substituted
  The problem is that if you compare a string field to a binary string, you can't replace the field with a string constant as the binary comparison may then fail (The original field value may be in a different case)
sql/item.h:
  Added Item::set_no_const_sub() to be able to mark fields that can't be substituted
sql/item_cmpfunc.cc:
  Mark fields compared as binary to not be substituted.
sql/item_func.cc:
  After merge fix
sql/log_event.cc:
  After merge fix
sql/mysql_priv.h:
  After merge fix
sql/opt_range.cc:
  After merge fix
sql/protocol.cc:
  Made flags uint instead of int (as it's used as a bit mask)
sql/protocol.h:
  Made flags uint instead of int (as it's used as a bit mask)
sql/protocol_cursor.cc:
  Made flags uint instead of int (as it's used as a bit mask)
  Indentation cleanups
sql/sp.cc:
  After merge fixes
  Removed compiler warnings
sql/sp_head.cc:
  After merge fixes
sql/sql_base.cc:
  After merge fixes
  Removed 'send_error' from 'insert_fields()' as the error is sent higher up
sql/sql_class.cc:
  Give assert if set_n_backup_item_arena is used twice
sql/sql_class.h:
  Give assert if set_n_backup_item_arena is used twice
  After merge fixes
  Added 'simple_select' method to be able to quickly determinate if a select_result is a normal SELECT
sql/sql_handler.cc:
  After merge fixes
sql/sql_parse.cc:
  After merge fixes
sql/sql_prepare.cc:
  After merge fixes
sql/sql_select.cc:
  After merge fixes
  Moved 'build_equal_items' to optimize_cond() (logical place)
sql/sql_table.cc:
  After merge fixes
sql/sql_trigger.cc:
  After merge fixes
sql/sql_update.cc:
  After merge fixes
  (This should be fixed by Sanja to have lower granuality locking of tables in multi-update)
sql/sql_view.cc:
  After merge fixes
sql/sql_yacc.yy:
  After merge fixes
  Don't have FOUND as a reserved keyword

sql/sql_class.cc

@@ -165,6 +165,9 @@ THD::THD()
    in_lock_tables(0), bootstrap(0), spcont(NULL)
 {
   current_arena= this;
+#ifndef DBUG_OFF
+  backup_arena= 0;
+#endif
   host= user= priv_user= db= ip= 0;
   catalog= (char*)"std"; // the only catalog we have for now
   host_or_ip= "connecting host";
@@ -795,10 +798,13 @@ void THD::rollback_item_tree_changes()
 {
   I_List_iterator<Item_change_record> it(change_list);
   Item_change_record *change;
+  DBUG_ENTER("rollback_item_tree_changes");
+
   while ((change= it++))
     *change->place= change->old_value;
   /* We can forget about changes memory: it's allocated in runtime memroot */
   change_list.empty();
+  DBUG_VOID_RETURN;
 }
 
 
@@ -1585,16 +1591,24 @@ void THD::end_statement()
 void Item_arena::set_n_backup_item_arena(Item_arena *set, Item_arena *backup)
 {
   DBUG_ENTER("Item_arena::set_n_backup_item_arena");
+  DBUG_ASSERT(backup_arena == 0);
   backup->set_item_arena(this);
   set_item_arena(set);
+#ifndef DBUG_OFF
+  backup_arena= 1;
+#endif
   DBUG_VOID_RETURN;
 }
 
 
 void Item_arena::restore_backup_item_arena(Item_arena *set, Item_arena *backup)
 {
+  DBUG_ENTER("Item_arena::restore_backup_item_arena");
   set->set_item_arena(this);
   set_item_arena(backup);
+#ifndef DBUG_OFF
+  backup_arena= 0;
+#endif
 #ifdef NOT_NEEDED_NOW
   /*
     Reset backup mem_root to avoid its freeing.
@@ -1605,6 +1619,7 @@ void Item_arena::restore_backup_item_arena(Item_arena *set, Item_arena *backup)
   */
   clear_alloc_root(&backup->mem_root);
 #endif
+  DBUG_VOID_RETURN;
 }
 
 void Item_arena::set_item_arena(Item_arena *set)