Encapsulated user sessions.

This library is a simple object oriented alternative to the $_SESSION superglobal allowing application code to be passed encapsulated SessionStore objects, so areas of code can have access to their own Session area without having full read-write access to all session variables.

Sessions are addressed using dot notation, allowing for handling categories of session data. This is particularly useful when dealing with user authentication, for example.

---

Example usage: Welcome a user by their first name or log out the user

if($session->contains("auth")) {
// Remove the *whole* auth section of the session on logout.
	if($action === "logout") {
		$session->delete("auth");
	}
	else {
// Output a variable within the auth namespace:
		$message = "Welcome back, " . $session->getString("auth.user.name");
	}
}
else {
// Pass the "auth" store to a class, so it 
// can't read/write to other session variables:
	AuthenticationSystem::beginLogin($session->getStore("auth"));
}