Update crochet to use mkimg and mkfs

[teverett]

Update crocket to use mkimag and mkfs rather than mdutil. This would allow crochet to run without root and potentially in jails also.

makefs

mkimg

[brd]

I suppose the only problem with this is mkimg was added to FreeBSD in 10.1. So we could add a check that only uses it on anything after 10.1.. or if it is present.

[kientzle]

Adrian Chadd posted a working proof-of-concept of this:

https://github.com/erikarn/rpi-build

[kientzle]

Adrian's announcement and discussion is here:

https://lists.freebsd.org/pipermail/freebsd-arm/2014-December/009856.html

[citrin]

10.3 is oldest officially release now, so we can assume that makefs and mkimg are present on a build host.