Merge branch 'jc/merge-blobs'

Update the disused merge-tree proof-of-concept code.

* jc/merge-blobs:
  merge-tree: fix d/f conflicts
  merge-tree: add comments to clarify what these functions are doing
  merge-tree: lose unused "resolve_directories"
  merge-tree: lose unused "flags" from merge_list
  Which merge_file() function do you mean?

diff --cc Makefile
Simple merge