V.4.0 api

Упростил всю эту покипасту на 

```js
// Filtering categories out
if (filterConf.filter && filterConf.filter.cats && !_this.filterCats(value, key, 0, filterConf.filter.cats)) return;
if (filterConf.filterOut && filterConf.filterOut.cats && !_this.filterCats(value, key, 1, filterConf.filterOut.cats)) return;

// Filtering by existing and not empty fields
if (filterConf.filter && filterConf.filter.fields && !_this.filterFields(value, 0, filterConf.filter.fields)) return;
if (filterConf.filterOut && filterConf.filterOut.fields && !_this.filterFields(value, 1, filterConf.filterOut.fields)) return;

// Filtering by tags
if (filterConf.filter && filterConf.filter.tags && !_this.filterTags(value, 0, filterConf.filter.tags)) return;
if (filterConf.filterOut && filterConf.filterOut.tags && !_this.filterTags(value, 1, filterConf.filterOut.tags)) return;
```