Update rtai source location after changing to multi-source pkg

This is now a multi-source package.  The RTAI tarball is grabbed from
the rtai-source package and added to this one at configure time.
Re-enable rtai
Add missing RTAI ipipe configs
Add debug output

- Add debugging for when debian/control-real is remade unintentionally
  - That target depends on so many things, it's hard to tell why it's
    remade
- Add info to Xenomai and RTAI kernel patch manipulation output for
  readability
Remove redundant unpacking of kernel source
RTAI featureset rules:  fix hook into debian configure scripts

When debian/control depends on the RTAI source tarball, it gets remade
when we don't want it to.
Add changelog entry & bump release
Fix RTAI build source directory location

...and relative paths
Don't ask questions during patch

If there's a problem, just fail.