Release 3.1.0

[MisterGuinness]

1. When code is stable

• [x] Create a new release-v3.1.0 branch off the develop branch

  2. Create code changes for the release

  2.1 Update the Version Number

• [x] Checkout release-v3.1.0
• [x] Change the version in configure.ac

  2.2 Refresh Translation Files

  Note: Updating version and gettext "_(...)" references, not the actual translated text

• [x] Run redo_pot.sh
• [x] Review new.pot and if ok rename to [package].pot
• [x] Run redo_po.sh
• [x] Review new_[lang].po and if ok rename to [lang].po

  2.3 Documentation

• [x] Change readme.md for new version

  2.4 Apply changes to github

• [x] Commit
• [x] Push into release-v3.1.0

  3. Finally

• [x] Pull request & merge into master
• [x] Create a release (target master, which just got merged into)
• [x] Checkout develop and merge master to be sure all up to date again (esp version number change and fixes to release)
• [ ] Delete the release branch (if no longer required)