Merge pull request #600 from bolt/contenttypes-ignore-double-underscores

Ignore contenttypes that start with `__`, and slug always overrules key

Merge pull request #598 from bolt/feature/frontend-locale-switcher

 Locale switcher (language select) for the frontend.

Update CopyAssetsCommand.php

Merge pull request #583 from bolt/hotfix/distinguish-new-untitled

Distinguish between editing "New Page" and "Untitled Page"

Merge pull request #582 from bolt/hotfix/taxo-controller

Fix taxonomy controller

Merge pull request #581 from bolt/hotfix/more-tiny-tweaks

Working on some more tiny tweaks

Merge pull request #578 from bolt/hotfix/dynamic-path-for-theme

Set Twig path for current theme dynamically.

Merge pull request #577 from bolt/release/bolt4.0.0-beta2

Preparing release 4.0.0 beta 2.

Merge pull request #570 from bolt/chore/cleanup

Cleanup

Merge pull request #563 from bolt/working-on-extensions

Working on Extensions