Expose LAV filter settings

- Change how A/V config classes are initialized to keep the List<string>
properties from getting duplicated entries due to serialization
- Add audio mixing config
- Add A/V codec control
- Add video HWA resolution control
- Add audio delay setting
- Add DRC setting
- Add channel expansion settings
- Add channel layout setting
- Add auto sync setting
Merge pull request #79 from babgvant/master

Expose LAV filter settings