trx_t: Remove dict_undo_list and dict_redo_list.

innobase_create_temporary_tablename(): Replace TEMP_TABLE_PREFIX with
a table name suffix "#1" or "#2".  In this way, the user can restore
precious data, should anything go wrong.  It is possible to reach an
inconsistent state, because the creation, deletion and renaming of
single-table tablespaces are not transactional.

ut_print_namel(), fil_make_ibd_name(), innobase_rename_table(): Remove
the special treatment of TEMP_TABLE_PREFIX.

Introduce TEMP_INDEX_PREFIX == 0xff for temporary indexes.  This byte
cannot occur in index names since MySQL 4.1.  However, it might have
been possible to use this byte in MySQL 4.0.

recv_recovery_from_checkpoint_finish(): Call the new function
row_merge_drop_temp_indexes(), to drop all indexes whose name starts
with the byte 0xff.

row_merge_rename_indexes(): Renamed from row_merge_rename_index().
Remove the parameter "index".

row_drop_table_for_mysql(): Unconditionally call trx_commit_for_mysql().

row_drop_table_for_mysql_no_commit(): Correct the function commit,
based on the corrected comment of row_drop_table_for_mysql().  Rely on
table->to_be_dropped instead of TEMP_TABLE_PREFIX.

ha_innobase::add_index(): Simplify the control flow.