recipes: drop all PR/PR_append/PRINC

* there is a plan to remove PRINC support
  let's remove all PR/PR_append/PRINC till we don't
  need to support upgrade path (which is already broken
  by PR_appends

  http://lists.openembedded.org/pipermail/openembedded-core/2013-May/079145.html

  also merge two consecutive blank lines in edited files
  (in most cases created by ^PR.* removal:
  for i in `git grep "\(\(^PR[ =]\)\|\(^PRINC[ =]\)\|\(^PR_append[= ]\)\)"| sed 's/:.*//g' | xargs`; do sed -i "/\(\(^PR[ =]\)\|\(^PRINC[ =]\)\|\(^PR_append[= ]\)\)/d" $i; sed -i "/^$/N;s/^\n$//g" $i; done

Change-Id: Icb647d7f1d0ed664458e9c6e188f63c74a3e73df
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>