CREATE TABLE and PS/SP": make sure that 'typelib' object for
ENUM values and 'Item_string' object for DEFAULT clause are 
created in the statement memory root.


mysql-test/r/ps.result:
  Test results has been fixed (Bug#14410)
mysql-test/t/ps.test:
  A test case for Bug#14410 "Crash in Enum or Set type in CREATE 
  TABLE and PS/SP"
sql/mysql_priv.h:
  typelib() function declaration has been changed.
sql/sql_table.cc:
  Supply the statement memory root to use in typelib() and
  safe_charset_converter() functions to ensure that objects 
  created during the first execution of CREATE TABLE statement
  are allocated in persistent memory of the statement.
sql/table.cc:
  Change typelib() function to require MEM_ROOT.