Optimizing the speed of UserInfo

All info from the SteamAPI just get requested once and then stored to
$_SESSION.
Compatibility to all previous scripts via the translation from
$_SESSION['steam_*'] to $steamprofile['*'].
Revert "Optimizing the speed of UserInfo"

This reverts commit c36e14e1cf5f73d26d7aa8ac64b4b9a1d3b48d63.