Allow the new major version to be used as well (lock-file remains at 3.x)

This was inline in the script, and later migrated to a twig template. This made us force the use of twig, or otherwise the template would not work for the old user interface. We shouldn't do that, and we should have a proper PHP template in place.

When we are logging something and the logger hasn't been initialized, the messages are deferred and flushed by a shutdown handler. However, when we initialize a session, we set the track ID in the logger, effectively initializing it with everything we need. When we log something and then load the session (or create it), any subsequent logs will be dumped, but the deferred logs will wait until shutdown, changing the order in which they were emitted.

This patch makes sure we flush the deferred logs as soon as we have a track ID (can either be set manually or by, most typically, loading a session). That way, we get those logs out as soon as we can, and subsequent logs entries will be dumped afterwards, keeping their relative order.

This closes #1107

* Force template to be rendered by Twig

* Fix column and index-size for MySQL only

This ensures that we don't break any existing modules by renaming a template from ".php" to ".tpl.php".

Old PHP templates are going to disappear anyway, so let's not break anything for a change that will be removed in the near future. We keep the .tpl.php extension though.

We have moved those translations (and more that were missing) to their own specific files, which makes it easier to manage them automatically. Then it no longer makes sense to keep these entries in the general translation files.

Like we were supposed to do three versions ago