Fix bug with flash bag. Thanks Symfony.
Work on flash bag.
Added hasFlash method to session.
Use table prefix in database sessions.
Fix type hints.
Has "has" check flash.
Fixing hasFlash.
Fix old input.
Tweak how flashes are set.
Refactoring some code. Adding a few tests.
Fix flash handling to be vastly simpler.
Remove unneeded method.
Added cookie session handler implementation.