pre_create function and one is now able to create table
without giving the column specifications for tables of types:
DBF, ODBC, MYSQL, CSV, and WMI (on Windows)

modified:
  sql/handler.h
  sql/sql_table.cc
  storage/connect/ha_connect.cc
  storage/connect/ha_connect.h
  storage/connect/mycat.cc
  storage/connect/odbconn.cpp
  storage/connect/plgcnx.h
  storage/connect/tabfmt.cpp
  storage/connect/tabmysql.cpp
  storage/connect/tabwmi.cpp