add many2many second field index
Improve nullable and server_default
add set_manytomany_index_reverse() to toggle many2many table index creation process
add MODELS_CONFIG config support, so you can put __mapping_only__ to it, just like:
[MODELS_CONFIG]
test = {'__mapping_only__':True}, it'll be available when using get_model
make_application can reenter
Modify changelog