Recipes come and go over time, so when a recipe gets deleted the history
for it goes away, which means that if you look back in time you do not
see an accurate picture - you only see the subset of recipes that are
currently present. Introduce an indirection between recipes and history
that allows for old recipes to persist (mostly in name only).
Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
