FreeNAS Code

o Add the disk size to the choices to install onto.
o Move the warning screen until AFTER the install disk choice screen
- in future versions we'll have an upgrade option there
o loop over install.sh: if it exists, the install is borked. The only sane
thing we can do is restart the install process.
o Simplify things somewhat.

Code cleanup. Also, eliminate dialog boxes for shutdown and reboot. Move install process earlier in the rc boot script... maybe we could just replace it with what we have in install.sh, since it isn't doing much anymore.

Overhaul cd creation. Use more of the products of NanoBSD that are
left around after the build to speed up the creation of images. Avoid
the whole zfs takes forever to drain issue by not using md at all.
Instead, we use makefs and working directories. We assume that we're
in a nanobsd build environment, and a future will actually build this
as part of the nanobsd build. We no longer use any artifacts that
need to be kept around: all the info we need is now built as part of
the nanobsd build, or can be derived from that.

Also, we need to include things with a full path for install.sh. Move
them to /etc/ix since /etc/include looked to weird :)

Copy all the files in the build/files directory to etc.

We're still at 75MB for the ISO image.

This boots and comes up to a menu.

PR

Move up after last move added extra /ix.