Integrate basic functionnalities

• The basic foncionnalities of Path are integreted in EpicPath
• __rtruediv__ is not working with path : Path / EpicPath will raise an error 😞
  • You should use __rfloordiv__ instead : Path // EpicPath 👍
  • __floordiv__ should work with everything Path was working (with __truediv__)
• Add the comparaison a < b means the file/folder a is included in the folder b
• property .str with is a shorter name for as_posix()
• property abs : return the absolute path (os.path.abspath) as an EpicPath class
• In place modification with the functions/methods:
  • +=
  • /=
  • .add() (equivalent to +=)
  • .append() (equivalent to /=)
  • .extend() (equivalent to several /=)