work on arbitrary "containers". The image rules are just
specializations.
* Added rules, a definition file (build/jam/NetBootArchive), and a shell
script for creating a gzipped tar archive containing kernel and modules
required for network booting (the contents may need some fine-tuning).
ATM it can be built via the haiku-netboot-archive pseudo target. It is
generated in the output directory (e.g. "generated").
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@21591 a95241bf-73f2-0310-859d-f6bbb57e9c96
