Without this, the new version of Stratigility complained about no
response being returned. Old versions were more graceful here, but
this is certainly more correct.
Now we have two extenders:
- `Extend\LanguagePack` is the "convention over configuration" loader
for complete language packs.
- `Extend\Locales` can be used to load files (by locale) from a given
directory - useful for extensions that bring along their own locales
in multiple different languages.
Refs #851.
With this change, session objects are no longer instantiated
globally, but instead created within a middleware during the
request lifecycle.
In addition, session garbage collection is integrated with
the already existing middleware for this purpose.
Symfony's component relies on PHP's native session functionality, which
is not ideal. It automatically sets its own cookie headers, resulting in
this issue: https://github.com/flarum/core/issues/1084#issuecomment-364569953
The Illuminate component is more powerful and has a simpler API for
extension with other drivers and such, and fits in nicely with other
components we use (the majority of which are from Illuminate).
The gathering and execution of extenders can actually be done here
in the `Extension` class. This way, the `ExtensionManager` only
deals with the question of which extensions are enabled, the
`Extension` class actually extends the core application, and the
service provider simply calls a method, without having to know
about internals.
Aliasing was only working for the `src` directory, it would not find
modules in the `lib` directory. Therefore the easiest way to migrate
will be to remove the prefix manually from import statements.
