new file:   storage/connect/tabmgo.cpp
  new file:   storage/connect/tabmgo.h
  modified:   storage/connect/ha_connect.cc
  modified:   storage/connect/mycat.cc
  modified:   storage/connect/plgdbsem.h

Fix crash when dbname is null forJSON MGO tables
  modified:   storage/connect/tabjson.cpp
  modified:   storage/connect/tabjson.h