Merge branch 'jc/fix-tree-walk'

Merge branch 'jc/fix-tree-walk'

* jc/fix-tree-walk:
  read-tree --debug-unpack
  unpack-trees.c: look ahead in the index
  unpack-trees.c: prepare for looking ahead in the index
  Aggressive three-way merge: fix D/F case
  traverse_trees(): handle D/F conflict case sanely
  more D/F conflict tests
  tests: move convenience regexp to match object names to test-lib.sh

Conflicts:
	builtin-read-tree.c
	unpack-trees.c
	unpack-trees.h