v0.4.0

• module process_slim_mapper added. the module contains functions for
  automated processing of SLIM mapper bitmap images as obtained from test rigs
  by PCS Instruments.
• fixed a bug that lead to a permission denied error using the import_del
  function (and related functions) if the imported file is in the current working
  directory and the function is called within a program that runs in an IDE.
• docs theme changed to guzzle sphinx due to unresolvable compile problem with
  rtd