Fixed deprecated name path.py in favor of path

[twdragon]

The title is self-describing. The current version 2.2 of path.py produces the following error:

File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1002, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 945, in _find_spec
  File "<frozen importlib._bootstrap_external>", line 1439, in find_spec
  File "<frozen importlib._bootstrap_external>", line 1411, in _get_spec
  File "<frozen zipimport>", line 170, in find_spec
  File "<frozen importlib._bootstrap>", line 431, in spec_from_loader
  File "<frozen importlib._bootstrap_external>", line 741, in spec_from_file_location
  File "<frozen zipimport>", line 229, in get_filename
  File "<frozen zipimport>", line 767, in _get_module_code
  File "<frozen zipimport>", line 696, in _compile_source
  File "/util/lib/python3.10/site-packages/path-2.2-py3.10.egg/path.py", line 886
    def mkdir(self, mode=0777):
                         ^
SyntaxError: leading zeros in decimal integer literals are not permitted; use an 0o prefix for octal integers

inherited from Python 2, now it is definitely deprecated. Closes #124

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Also fixes ruamel.yaml safe_load() function removal. Closes #151