Fixes to avoid errors from valgrind

Fixed problem with 'wrong packet number' in union


include/my_global.h:
  Fix for valgrind
mysql-test/t/rpl_rotate_logs.test:
  Fix to avoid timeing problem
sql/item.h:
  Indentation change
sql/set_var.cc:
  Fix to avoid reference to uninitialized memory
sql/sql_select.cc:
  More DBUG_PRINT messages
  Fixed problem with 'wrong packet number' in union (tmp_join.error was not correctly reset)
sql/sql_union.cc:
  Simple code cleanup
strings/ctype-simple.c:
  Fix for valgrind

mysql-test/t/rpl_rotate_logs.test

@@ -91,6 +91,7 @@ sync_slave_with_master;
 connection master;
 purge master logs to 'master-bin.000002';
 show binary logs;
+--sleep 1;
 purge logs before now();
 show binary logs;
 insert into t2 values (65);