FreeBSD support

[johnmarc]

I run my chia-node in a FreeBSD jail, but can't farm compressed plots on it due to a lack of Bladebit support currently. I work around this with a linux VM running under bhyve but it's a suboptimal solution. Chia-Blockchain mainline supports FreeBSD with very minimal effort and it'd be great if we could get the same level of support from Bladebit.