Known bugs, fixed here.

mysql.php throws a diferent than "PDOException". This leads to an ugly error page when a user tries to install to a database that doesn't exist. This catches the error. We might consider trying to create the database. Reference https://github.com/anchorcms/anchor-cms/issues/638
I'm noob to php but isn't it should be ````"mysql:host=".$database[host],```` instead of this?