include/mysql_com.h:
  remove "shutdown levels" that aren't shutdown levels from mysql_enum_shutdown_level
mysys/my_addr_resolve.c:
  my_snprintf in 5.5 (but not in 5.3) supports %p
sql/item_func.cc:
  use a method (that exists only in 5.5) instead of directly accessing a member
sql/item_subselect.cc:
  use a method (that exists only in 5.5) instead of directly accessing a member
sql/opt_subselect.cc:
  use a method (that exists only in 5.5) instead of directly accessing a member
sql/sql_select.cc:
  use a method (that exists only in 5.5) instead of directly accessing a member