This update for virtualbox fixes the following issues:

- Version bump to 5.0.30.
- Storage: fixed resizing VDI images resulting in an unbootable image under certain circumstances.
- NAT: fixed several 5.0.28 regressions on Mac OS X and Windows hosts.
- Audio: fixed recording glitches. (Mac OS X hosts)
- Audio: fixed stream re-initialization on audio device change. (Mac OS X hosts)
- Linux hosts / guests: Linux 4.8 and 4.9 fixes.