4.1 Exercise 1
  Problem
  Conflict
  Resolution
 4.2 Exercise 2
  Conflict
  Resolution
 4.3 Exercise 3
  Conflict in path.c
  Conflict in builtin/pack-objects.c
 4.4 Exercise 4 - a git conflict
  CB in contrib/completion/git-completion.bash
  Working from UB (keeping markers for clarity)
  Get dML
  Apply dML on UB
  Result
 4.5 Exercise 5 - another git conflict
 4.6 Exercise 6
  dMU
  dML
  Resolution
 4.7 Exercise 7
  CB in diff.h
  CB in builtin/diff.c
  CB#1 in diff-no-index.c
  CB#2 in diff-no-index.c
  CB in diff.c
 4.8 Exercise 8 - using the script