grim v1.3.1

Adrian Ratnapala (1):
      Explain that '.' is grim's final fallback dir

Daniel Playfair Cal (1):
      Correct interpretation of output rotation

Gilles Talis (1):
      Fix maybe-uninitialized warning

Jason Nader (3):
      Add completions for fish-shell
      completions: add missing option
      Improve error message for when supplied region is invalid

Robin Karlsson (1):
      fix bufferoverflow in output_filepath

Simon Ser (2):
      contrib/completions: fix fish file path
      contrib/completions: fix unset datadir variable