Merge branch 'release/0.4.0' into develop

* release/0.4.0:
  Update version to 0.4.0
Merge branch 'hotfix/0.4.1' into develop

* hotfix/0.4.1:
  Version update
  Update documentation
Require input file when overwriting an output file
Increase version
Merge branch 'release/0.4.2'

* release/0.4.2:
  Increase version
  Require input file when overwriting an output file