Fixed "Waiting for driver...", added driver integrity check

Many users have reported problems with installing the new driver, so we revised the process and fixed several bugs along the way. Please restart Steam to ensure you have the update. This update also fixes buttonless activation for some new SteamVR users, and fixes with Joycon/PSMove. If you still have issues please comment below what headset you have and then revert to the old version: [img]{STEAM_CLAN_IMAGE}/32383436/3e882462ebc51940eb03e7c337977c299ad230d5.gif[/img]