add command line handling for pxe generating

Signed-off-by: Nico Schottelius <nico@bento.schottelius.org>
create kernel, pxeconfig and pxelinux.0

Signed-off-by: Nico Schottelius <nico@bento.schottelius.org>
create initramfs

Signed-off-by: Nico Schottelius <nico@bento.schottelius.org>
disable unsupported iso - create /init - include support for another initial manifest

Signed-off-by: Nico Schottelius <nico@bento.schottelius.org>
inet not init

Signed-off-by: Nico Schottelius <nico@bento.schottelius.org>
update preos notes

Signed-off-by: Nico Schottelius <nico@bento.schottelius.org>
fix 'stdin: is not a tty' problem (thanks, steven)

Signed-off-by: Nico Schottelius <nico@bento.schottelius.org>