merge: include ancestor node in merge actions
merge: keep destination filename as key in actions for merge with dir rename

Avoids
   None: local renamed directory to b/c -> d
  updating:None 1/1 files (100.00%)
and makes it possible to compare/merge actions later.
merge: keep destination filename as key in filemerge actions

Gives more readable debug output and makes it possible to compare/merge actions
later.