Merge branch 'feat/config_support'

Closes #5.

* feat/config_support:
  Read system level configs.
  Support per directory config file.
  Make coloured output selectable in config file.
  Support subcommand defaults in config file.
  Add --no-backup option.
  Read --directory setting from config file.
  Added config file reading.
  Added XDG basedir config handling.