add forgotten stamps/ dir to 0.1.base-builddeps target
Add number and variant to logs; add keyring dep to chroot build

- Hopefully task numbers and codename/arch in the logs (e.g. '3.2
  jessie/i386') will make this more comprehensible

- The ubuntu keys are needed in the keyring to build ubunte chroots!
.gitignore:  clean cruft
Add clean and squeaky-clean targets to Makefile

- Add clean targets for each step
- Add handy 'CA_EXPAND' function
- Make many deps more explicit
  - Easy, now that targets are all numbered
- Only build xenomai source pkg once
Fix make clean recipes

Apparently {brace} and [bracket] expansion doesn't happen in the make
shell.  Expand everything.

Add clean-chroot-update.

Add squeaky-clean-cache and codename/arch/clean targets.
Fixups:  xenomai source pkg path; create ppa subdirs
Set up linux kernel source package in a chroot

The kernel source package needs to be configured before it can be
created with dpkg-source.  During this step, the i-pipe patch is taken
from the linux-patch-xenomai package and added as a feature set patch.

The linux-patch-xenomai package is generated in this same system, and
can't be expected to already be installed on the host.  Instead,
configure the source package from within a random chroot.
fixup for stamp cleanups
Doc updates