compare_dirs, move subs from Ningyou

* add more verbose output
* remove some indentation
* add sub 'compare_dirs' that uses  File::DirCompare to
  compare directories in a simple way. However it do not
  compare the mode rights on file system level
* move ask_to_create_directory from Ningyou
* move ask_to_create_worktree from Ningyou