now we execute only one first select during mysql_real_query
others - during 'mysql_next_result'


include/mysql.h:
  'virtual' next_result added
libmysql/client_settings.h:
  cli_next_result declaration added
libmysql/libmysql.c:
  mysql_next_result now works in embedded library as well
libmysqld/lib_sql.cc:
  emb_next_result implemented
sql/sql_class.h:
  fields to store the rest of the query added
sql/sql_parse.cc:
  Saving the rest of the query added for embedded case