Fix flavorset tweaks to enable multiple featuresets with different needs

Fixes to turning off 'none' featureset
- Don't build irrelevant arch-indep packages

Fix build for unconfigured featuresets
- Include only rules.featureset-* for configured featuresets
  - Facility for adding 'include' to rules.gen
  - gencontrol --list-featuresets option for use in scripts

Support featuresets that bring in modules from outside:
- Fix objcopy --add-gnu-debuglink command, which assumes that all
  modules are in /lib/modules/<kver>/kernel
- Add hook in rules.real for rules.featureset-*
- Add hook to kernel install recipe for modules to be inserted into
  install tree
Add patch:  fix build error during module install

make[6]: *** No rule to make target '/tmp/buildd/linux-3.5.7/debian/linux-image-3.5.0-1mk-xenomai-686-pae/lib/firmware/./', needed by '/tmp/buildd/linux-3.5.7/debian/linux-image-3.5.0-1mk-xenomai-686-pae/lib/firmware/atmsar11.fw'.  Stop.
make[6]: *** Waiting for unfinished jobs....

https://bugzilla.kernel.org/show_bug.cgi?id=39192