Add git/linux/debian submodule; teach Makefile to download it
Makefile:  Fix non-anonymous xenomai git url
Makefile:  teach to download linux tarball
Makefile:  build linux-source packages

.gitignore unpacked linux tarball files
README:  remove a bunch of useless junk
Move configuration into pbuilderrc; first try at including local pkgs

- pbuild directory with conf & hooks
- Makefile doesn't care about which codenames belong to ubuntu or debian
- Config moved to pbuilderrc:  codenames, keyrings, other pbuilder options
- Try to include local pkgs;  currently bombs out because no sigs
Makefile:  don't throw away base.tgz intermediate files\!
Build linux; not quite working yet

- Refine src, git, etc. prerequisites
- linux debian submodule:  add build deps and bump release
Unify keyring:  one keyring for Ubuntu and Zultron sigs
Makefile:  partial fix to kernel submodule updates
Install local deps from deb.machinekit.net

Giving up on trying to do everything locally for now
Makefile:  cosmetic fixes
Makefile:  exclude .git & other cruft from source pkgs
Update target list; add TODO section