rewrite most of installer & remove ksh93 dep
this started as a removal of the ksh93 dependency, but we don't really
need most of the logic in the installer runtime, so simplify that as
much as possible.
additionally, simplify installer generation: don't create a miniroot and
compress it just to uncompress it and copy files from it to another
miniroot, and don't compress with bzip2 -- it takes too long. this does
increase the image size, but jeff compresses the release images anyway.
29 files changed: