mutex protecting thd->open_tables".

We should not manipulate with table->s->version outside the 
table definition cache code, but use the TDC API
to achieve the desired result.

Fix one violation: close_all_tables_for_name().

sql/sql_base.cc:
  Use tdc_remove_table(TDC_RT_REMOVE_ALL) to expel the
  table share in close_all_tables_for_name, rather
  than manipulate with the table cache explicitly.
  
  Make sure that close_cached_tables() calls 
  close_all_tables_for_name() after closing all the involved
  handlers. The rest of the code was inspected to
  make sure that mysql_ha_rm_tables() is called.
sql/sql_handler.cc:
  Add a method to close all HANDLER cursors for a list
  of tables.
sql/sql_handler.h:
  Add declaration for mysql_ha_flush_tables().