Whenever we update the tree with new informations, all the sibilings
needs to be updated as well
Also switch to inmemory db for recipe - even if this should be a switch
Split dependency resolving ( definition <-> db mapping ) into a method of the tree (ResolveDeps),
and do not care of looking up for packages while parsing.
Note: it is slower but it is much accurate and we can
choose what to do with the ones which aren't resolved (and show a helpful message too).
