Add checking of model definitions

1. Simplify the judgment statement

if( domain === namespace && !!handler ){
return handler( state, action );
}else{
return state;
}

now it is like below

return domain === namespace && !!handler ? handler(state, action) : state;

2. initStore function can be load extra data now, the loaded data must be saved by using store.getState(), the extra will cover your defintion init state data

const redux_dva = require('redux-like-dva');
redux_dva.add(require('any_model.js'));
const data = JSON.parse(fs.readFile(/*your data file*/));
const store = redux_dva.initStore(data);

Add subscriptions field, this field's content will be execute auto after load all reducers and sagas