PDO object in the PDOSessionHandler not created

[skroczek]

Playing with the WebsocketAppDemo, I stumbled over an issue with the VirtualSessionStorage with pdo_sqlite as storage.
It turned out that there was no PDO object in the PDOSessionHandler if the database connection is defined as DSN string. To solve the issue you have to call PdoSessionHandler::open, and since this method is defined in the SessionHandlerInterface it should be save to call it every time (In the MemcacheSessionHandler it always returns true, for example.).
To solve this issue, I created the pull request #351 some time ago.

[cboden]

Thanks @skroczek! I'll have some time in about a week to review that and other open PRs and release v0.3.4. Thanks for your input and my apologies for the delay.