Move stamps around; chroot login target; disable vanilla kbuild

- Rationalize some stamps:  put into /stamps/ directory
  - Add rudimentary numbering scheme to hint at build order
  - Need the rest in there, too
- Add <distro>/<arch>/chroot target to log into chroot
- Fix problem where linux-tools don't unpack a second time
- kernel-rt-deb2 submodule:
  - disable vanilla kernel build
  - fix build dep to build on precise
- Print more diagnostics in pbuilderrc
  - Precise builds breaking on kernel build; not sure why
Add jessie; remove lucid and squeeze; fix build problem

Add jessie

- Jessie won't allow package revisions with 3.0 (native) format pkgs
  - fix in submodule
- Fix (kludge) a build dep
- Clean up orphaned hardy config

Lucid isn't supported by new kernel packaging, which requires python
>= 2.7 (2.4 available), kernel-wedge >= 2.82 (2.29 available),
gcc-4.6 (4.4 available).

Squeeze (Debian 6.0) is reportedly obsolete.

Fix problem when leftover obsolete xenomai source pkgs break build