Adds virtio-console device support to bhyve, allowing to create bidirectional character streams between host and guest.
Maximum of 16 ports per device can be created. Every port is named and corresponds to an Unix domain socket created by bhyve. bhyve accepts at most one unix domain socket connection per port at a time.
- due to lack of destructors of in bhyve, sockets on the filesystem must be cleaned up manually after bhyve exits
- there's no way to use "console port" feature, nor the console port resize as of yet
- emergency write is advertised, but no-op as of yet