Fixed handling of lower_case_table_names in SHOW TABLE STATUS,...

Fixed handling of lower_case_table_names in SHOW TABLE STATUS, mysql_list_fields() and mysql_table_dump().
This fixes some Errcode 13 errors on Windows when deleting tables.



sql/mysql_priv.h:
  Moved lower case conversion of database names to check_db_name()
sql/mysqld.cc:
  Fix to be able to use 4.0 error message files
sql/sql_db.cc:
  Moved lower case conversion of database names to check_db_name()
sql/sql_parse.cc:
  Moved lower case conversion of database names to check_db_name()
  Added checking of lower_case_table_names for mysql_table_dump() and
  mysql_list_fields()
sql/sql_show.cc:
  Moved lower case conversion of database names to check_db_name()
sql/table.cc:
  Convert database names to lower case in check_db-name() if --lower-case-table-names is used.