Filter 'andOperator' per Filter instead of globally

This is a feature request:

Adding Filters individually with a boolean operator, instead of having one boolean operator for connecting all filters.

Example:

Now all filters are applied either by the AND operator or OR operator, which means expressions like:
```
filter1 && filter 2 && filter 3 && filter 4
filter1 || filter 2 || filter 3 || filter 4
```

It would be great to be able to add filters individually with their preceding operator to the filter chain.
```
source.addFilter(filter1, false);
source.addFilter(filter2, true);
source.addFilter(filter3, false);
source.addFilter(filter4, true);
```
would result in the following filter chain:
`filter1 && filter2 || filter3 && filter4`