INNOBASE_SHARE: remove

check_index_consistency(): iterates through keys and looks for InnoDB and .frm
mismatches.

ha_innobase::innobase_get_index(): now uses dict_table_get_index_on_name()

dict_table_get_index_on_name(): uses strcmp() instead of innobase_casestrcmp()
as we just need to know whether strings are equal or not